The composing room measured 6.43 by 4.45 metres. There were two west-facing windows and one south-facing. During the day, light from three windows came from two directions.
The outside walls were thick, but ambient sounds must have penetrated. Sounds with which you could determine the time, as you could by the incidence of light. Breaking through the accelerated passage of time that occurs with hyperconcentration.
Habits of family life, modern music of kitchen noises, footsteps on the stairs, slamming doors, singing of Anna Magdalena and that of her talented songbird - a linnet, the unmusical croaking counterpoint of a nearby crow, the house was a dovecote of guests and visitors, children practicing, the daily program of the indoor school for boys, the activities in the adjacent church, the ringing of the bells of many churches, street noise, city life, a hailstorm, sounds of the weather in connection with the seasons, all rhythms and tones, the world makes itself heard.
Together a muffled cacophony that must have occasionally penetrated into the inspired focus of composing and calligraphy. Distracting, telling how much time was left to get the job done, being needed, things that need to be done, the attention-grabbing dynamics of here and now, contrasted with the artistic challenge of making music forever and everywhere.
The photo shows an empty room. But we can sum up what must have been there, an inventory of things, the tools Bach needed and used.
The cabinets may have belonged to the same carpenter, and could have looked like the one's in the photo, taken in the working room of the Thomas school.
There must have been a table where the light caught the eye, directed to the window so as not to be affected by cast shadows, and where he could place his brandy, which he preferred to have in the solitude of his composing room. Smoke, alcohol and sugar rush would have an impact on his mood, mind and motor skills. In 1735, Bach received a drinking glass as a gift, with music engraved on one side.
Traces of burning tobacco crumbs can hardly be found on the manuscripts. We can deduce that Bach used tobacco and brandy when composing from an expense note for a job application in Halle in 1708, it is a factual substantiation for only 1 case, but we can extrapolate it.
Bach smoked tobacco with a clay pipe, which often burst in his hand (BWV 515: I'll smoke therefore contentedly on land, at sea (Beethoven mentoined he should be named Oceaan instead of Brook) and in my house). There will have been a new pipe ready to quickly transport over the burning contents.
However, things have not always gone well. It is precisely with the carefully calligraphed score of BWV 244 The St Matthew Passion that things went completely wrong with the cover and first 13 leaves. We can no longer see what the damage was, it's a known unknown, but Bach may not have been a happy pipe smoker at the time. Bach had to work as a restorer of his own manuscript. He cut off a wide strip of paper of the cover & 13 pages, glued new ones to it, and rewrote the words and music. Bach might have had paper glue: bone glue, and a brush at home and handled it skillfully.
Anna Magdalena is remembered with an always fresh bouquet of yellow carnations. An impact-sensitive object containing water that you do not like to have on your work table.
It is comforting to have a portrait of your loved one in your workplace. Carl Philipp Emanuel's estate records a portrait of Anna Magdalena painted by Antonio Christofori, it may have hung here in plain sight adding some cossiness and virtual company to Bach's man cave.
Anna Magdalena made at least eight fair copies of voluminous works, it was an important source of income and an act of love. She had access to his materials, the same space, and she see saw how he did it.
Even when the handwriting is hasty, the workplace was kept neat. There are not many signs of wear from turning the pages or from storing or transport. Signs of use and wear from physical contact by studying, rehearsels or performances are also almost absent, such as, for example, due to saliva from singers. (Bach's son Wilhelm Friedemann, who inherited a substantial part of the scores, now partly lost, charged a substantial fee for being allowed to see a score for a day.) The scores were usually treated with care and respect, whatever their future fate might have become.
Pages were sometimes turned quickly during playing. Paper can handle that, it's made for it. There is no need to wear gloves to protect the paper, it is even safer and more durable not to, your hands are precision instruments. Paper is surprisingly strong.
He must have lit his tobacco and candle with a matchstick, a thin piece of wood dipped in molten sulphur, the forerunner of the match.
As a young boy, Bach had secretly copied his older brother's scores by moonlight for six months (their handwriting look alike). That wouldn't have been possible in the ashen glow of a new moon or with an overcast sky. A held back candle would have been a godsend.
Three types of candles were available: made of cow or sheep fat, beeswax or whale wax. Cheap, affordable or expensive respectively and in the same order smelling horrible, delicious or neutral. Candles gave heat and burn regularly at a rate depending on their substance, so you could read the passage of time. A single candle on the table will have sufficed, several candles cost more and create a restless range of cast shadows, visual noise that may have been deliberately avoided. Painters loved this setting, for its intimate chiaroscuro.
During cold days, a footstool would have been nice, by putting a blanket or piece of clothing over the legs and the stove, the heat was retained and the lower legs were also heated. Heating affects humidity and therefore paper: sheet size, long-term preservation and writing resistance. Cut a sheet of paper measured with a ruler during a period of continuous rain and later during a period of continuous heat and you will end up with two sizes: paper lives.
Bach must have sat on a chair with his corpulent body. On Johann Emanuel Göbel's portrait part of a backrest is visible. Chairs were comfortably upholstered in strong fabrics. A second chair was for his guests, such as the libertist Christian Friedrich Henrici, writing under the pen name Picander.
Many writing desks from his time have been preserved because they are so robust, nice and practical. We can make a general description of what it probably looked like. Local oak was usually used, but other massive species such as walnut and chestnut were also common. The rectangular table had an H-shaped spacer at the bottom of the legs, where you could put your feet. The legs were machined on a lathe. The tabletop was equipped with several drawers. The style, like his wig, can be classified as Louis the Fourteenth (a Bach number, he must have felt connected and familiar with this vicar of God on earth, a king in his own cave).
After Bach's death a list of possessions was drawn up - it shows a collection of instruments. Bach might have had instruments on hand at his working room. That was not necessary, his experience and imagination could play it off. The size of the collection, the limited space of the house, the many people, and the fragility of expensive instruments would make it a practical choice keeping a large part at his playground.
There are compositions that originated from improvisations, which he could later write down from memory. A little play in between could have been relaxing, or clarifying to explain something to someone.
The term keyboard in Das Wohltemperierte Klavier is a collective term. Many have done their best to exclude a specific instrument as the ultimate choice. For example, a long sustained bass note is an argument to plead in favor of the organ and to exclude other keyboard instruments. The argument that can be made against this is that a tone does not have to sound audible for a long time in order to continue to function harmonically. Collections that can be played on a wide variety of instruments have a larger target group, which can lead to better sales results.
Mentally, we should switch from the either or question and learn to see the set of instruments themselves as the answer. Making such a step is an insightful solution to many problems that linger with Bach and may do him more justice than the search for the one answer. Either or discussions are fruitful for emphasizing details, while an anything will suffice attitude can block your powers of observation and make you sloppy in your pursuit of making the best of it.
An instrument that is hardly mentioned in literature, but which was likely in his composing room, was the lute-harpsichord. It is enriching to delve into its characteristics in order to get an idea of all the possibilities that Bach had at his disposal.
Bach could use the penknife he used to prepare his writing quill to maintain the pens of his lute-harpsichord. (Youtube: Cutting and voicing plectra using bird's quill).
The creation of both parts of the Wohltemperierte Klavier coincides with the purchase of a lute-harpsichord.
The
instrument was an invention of Johann Nicolaus Bach: a gut strung
keyboard. In 1706 Nicolaus had quickly tuned an organ in equal
temperament relying on ear and experience.
The
sound of the lute-harpsichord could deceive a professional lutenist.
Nicolaus made them with two and
three manuals, whose keys sounded the same strings but with different
quills
and at different points, providing three grades of dynamic and timbre.
In 1720
Nicolaus Bach built a lute-harpsichord for his cousin Johann Sebastian
Bach in
Cöthen.
Unlike Bach, Galilei wrote clearly about music. He promoted equal temperament in his books and allready in 1589 tempered a keyboard in a Bavarian court that way, which was very sweet to hear.
Whatever
the precise tuning concept of Wohltemperiert, it is an
embracing of imperfections. The essence of Well Tempered is that good
enough is
better as perfect.
There is a range of possible variations that can satisfy and suffice, and in Bach's art that applies to many subjects: for example the way you play, which keyboard instrument to choose, how you write, which bird feather to choose, the opacity of ink, or the type of the paper you use.
This uninvited guest in C minor, a sad chord, detonates with the original. Analyzing Bach's calligraphy, his tools and materials, could also derail harmonically from historical reality. Caution is required, but also a certain daring and determination, we will have to make do with what we have.
The paper Bach had in front of him looked different from what we see now, not only because of discolouration, but also because it acquired all kinds of stains and additions. They can provide a kaleidoscopic testimony of Bach's environment and habits. Determination of those celestials objects is beyond our reach and objective, but we can let go of what we may be seeing.
Although no bug ate his fugues, his counterpoint might have been dusted by flour powder from his wig. A flea might be immortalized in the sticky drying ink like an insect in dark amber, with full stomach holding it like a Jurassic treasure. Candle drops, food and schnapps might have been captured. DNA transferred by wetting a dry quill with the tongue, several eyelashes, blood, sweat and tears. They are a gradual transition to the seismographic properties of drawn lines, which may be distorted by laughter, singing and shouting.
There is an entire underwater world of deep-sea creatures formed by splashes of ink and who knows what. You could probably put together a cookbook based on the analysis of stains left behind in Bach's autographs: Cooking with Bach.
Each folio is like a composite image by a space telescope, we can see all kinds of worlds, but we can't go to them.
Other features that are out of reach because of their nature are the so called Griffelglossen, scratches and writing that are only visible in grazing light. A relative of the watermark family.
Paper types and watermarks are time-bound, they can be dated with a few years of accuracy, it was generally not stored for long and only rarely purchased for later use.
The specifications of the above watermark indicate the period of use as 1739 - 1744, which does not correspond to the period of origin of the autograph, which runs from 1720 to 1739. We should therefore not blindly rely on this source of information.
Machine-made paper existed: cheaper, smooth, white and even - Bach did not use this.
He preferred handmade paper: rough, slightly tinted and uneven. The roughness can be compared to modern shorts of paper. There are many gradations and variations and they are crucial to the sensory experience and pleasure of handwriting. The pretty color was a result of the iron in the water used by the local papermakers and was also preferred by drawing artists for centuries. This is separate from the discolorations that are now dominantly visible and that are caused by the use of non-durable ink. Copying a score on good colored paper is a worthy goal in itself, it's a detail, but it matters.
Pulp fibers from ground cotton or flax were hand shoveled onto a sieve frame. With handmade paper there is no running direction, you can tear it either way because the fibers are randomly arranged by the scooping movement. The paper remains stable under many conditions but is sensitive to the effects of moisture, especially the air humidity is important to take care of.
Two types of paper can be clearly distinguished under the microscope: one is made up of thin, long white and transparent fibres, the other of shorter, light brown and cream-coloured bast, hemp and/or grass fibres.
Cotton fibers consist of a natural polymer and are often still of excellent quality. Wood or vegetable fibers contain components that are very sensitive to light, often clear light damage can be recognized. Gum arabic was added to prevent ink from running.
Paper has two sides; the "screen side" (=recto) and the "felt side" (=verso).
A ream of paper is a quantity of sheets of the same size and quality. Bach's manuscript paper at Weimar was ordered by the ream of 480 sheets. In Weimar Bach used double thick paper (this was designed exclusively for writing music) but later only used single thickness. Bohemian paper was good quality paper.
Paper owes its success to its cheap price, yet the full pages of Bach's manuscripts are often linked to the supposedly expensive price of paper. That's probably not true, in Leipzig Bach could at any time obtain the paper he desired in any quantity that he needed. For the reasons of efficient page filling, we will look at other arguments.
The scooped papers had more or less standardized formats: 33 - 42 centimeters for Kanzleiformat and 34 - 43 for a size that was called Propartia. Unfolded it was called a Bogen, folded once it became Folio, twice Quarto and trice an Octavo.
Bach generally used the Folio format. Subsequent owners of the manuscripts regularly cropped pages, for binding purposes, the human tendency to make everything even, or to get rid of frayed edges.
They are a reversal of the breathtaking beauty and theatrical effect of a watermark in reality which can be a never-beating surprise and a joyful experience. The naive depictions are reminiscent of the kind you also find on tiles, look at a few and suddenly there is one that moves you.
We now do it with the thermal images, which are not hindered by ink. Before that we had to make do with drawed reproductions by an untrained hand, which had little to do with the characteristics of the original threads.
The current and previous methods of watermark reproduction detract from this, they do not do justice to the feeling that a real life watermark evoke and seem to be detached from pleasurable sensory experience, while the scores already fatally cloaks itself in rust-brown shades due to acidification.
We cannot see where the watermarks are in the digital copies. This should be given further consideration.
A radical preservation method was used to slow down the process: affected sheets were pulled apart, the so-called paper splitting, and then re-glued with a reinforcing alkine sheet.
We can see from the example BWV 846 Prelude of the WTC that the split did not happen exactly from the edge. On the left, staff lines and key are even cut off.
A decent portion of the scores have undergone this treatment. Access to the originals is wisely very limited. To experience the sensation of holding this type of paper we will have to find paper that is similar. That's just a few clicks away if you know what to look for and select and will be delivered to you quickly.
Explore and experiment by trying different papers, maybe your local store has nice hemp paper. The key is not to look for special rare materials with special properties, look for what is common, and be content with that. For example, search for handmade cotton or flax paper, sized, slightly tinted, that is at least 33 by 43 centimeters, of regular thickness. That's exactly what you need. When you become a little familiar with it, you will notice that you have a preference for a certain species. Don't doubt, that's what you should be happy with, and use.
German paper mills have not been running for a long time, similar paper is now made in the north of India. Paper made from hemp is experiencing a revival because it is a durable and fine material. The difference between flax and hemp is minimal and negligible from a calligraphic point of view. Some modern hemp papers are the spitting image of the ones Bach used.
Making paper yourself is not very difficult, but grinding hemp fibers is labor intensive. If you prefer untrimmed deckled edges for a given size then DIY or by order gives you control. And you can design your own watermark. There is plenty of information on the web on how to do this.
It accelerated the acidification process and bonded with ink. The image above is a detached sheet of chiffon silk, with a negative print, like a Shroud of Turin. It has its own beauty, but you are staring at a trainwreck.
Spectral analysis has been applied to it to study the used ink. There is a huge variety of small amounts of elements like copper, manganese and zinc.
Staff lines may have been drawn on a different day. Different colors and opacity may indicate revision, there may be years in between. With every deviation we can ask ourselves: whose hand is this?
Bach used three colors of ink: brown, black and red.
The brown dye consisted of soot obtained from a butcher's chimney or burnt walnut shells, to which gum arabic had been added as a binder. Normalized color coordinates for bistre brown are identical to the color names drab, sand dune, and mode beige. The inkt was called bistre of bister. Old masters used it for their drawings. Celebrate the drab.
The brown inks are a true goldmine for our purpose. It's translucency throws off a lot of easy-to-read variables. Dip frequency, sequence, speed, pick up and drop, direction, and hand position immediately catch the eye. It is an emotional event to let that sink in, we are really close to Bach here. Thank God, I mean Bach, for that. Brown ink ussually does not have the harmful effects like the black one. The pages are a lot lighter in color, there is less discolouration.
Brown inks are only light sensitive when applied diluted. Writings made of bistre can gradually disappear when exposed to sunlight.
Brown ink based on iron gall ink also existed, ink corrosion occurs with brown and black inks.
Fading of reds can be seen in the St. Mattew score. Red ink was also the choice for the handwritten corrections to the engraved prints of Clavier-Übung III. Right or wrong was not an intrinsic value of the meaning of the color, but depended on the context.
The mineral dye vermilion was the basis of every recipe for red ink, egg whites and lemon were used to create shades.
The small inkwell on the table was constantly replenished, like an eternal French broth. It takes a day for the gall nut ink to take on its black or heavy brown color from oxidation, it has a sepia brown color when applied, like bister. Temporary dyes were therefore added, some gall nut inks had a brilliant deep skyblue color in the bottle. Temporary purple shades could be made with non-lightfast dyes such as bluewood. The color spectrum during writing was therefore much wider than what we can see of it now. A bright blue or deep purple score will not easily give the impression of being historically correct, yet may be exactly what Bach saw for a day when writting. About two hundred written relevant recipes have come down to us, many will not have be written down but simply done.
Until the second half of the eighteenth century, ink was sold loose from a barrel, the buyer himself had a vase or jar for this purpose. It was not until the second half of the eighteenth century that ink was sold pre-packaged (in an inkwell made of earthenware and later of glass).
It required two tricks that had to be done without a mess: filling the jar with ink at the vendor's and regularly refilling the inkwell on the desk. Lots of ink going in at once versus a more controlled going out in small amounts. The jar had a wide base to prevent falling over and a narrow neck with a loose spout for pouring.
There are three basic elements in gall nut ink. This ink was made from iron salts obtained by treating iron with sulfuric acid. This iron was mixed with oil from gall nuts and a thickener, usually gum arabic. Traces of the earliest powdered ink dates from 1680, which gained popularity in the 18th century, especially for travelers, but Bach's scores do not show he used it.
During the day ink could thicken through evaporation, the viscosity became stronger. The thicker the ink, the more ink corrosion. Thin gallus ink lines can be light sensitive.
Black ink naturally gives a higher contrast than brown, and thus increases readability of notes. You can also appreciate it aesthetically differently. If black ink is your preference, high quality gouache is an excellent alternative to use as ink, it dries nicely matte. Gallnut ink is still available, you can even have ink put together to order at your own discretion, if you don't work for eternity and want to get to know the stuff personally you can.
Not recommended is India ink, the shellac it contains contracts the paper when it dries, a tension we like to avoid, in addition it is quite shiny at certain angles, we don't like that.
In addition to dipping, ink can be dosed accurately by using a brush as an intermediary between inkwell and nib.
Ink has to dry and with high humidity and deep concentration, seconds become an eternity before a page can be unturned. The assessment of whether everything has dried properly is negatively influenced by the urge to continue working. Small tailed comets testify to early decisions, often in the same direction, from bottom left to top right. Sometimes with a mirrored parallel, less brighter satellite on an opposite page. His tabletop must have been a busy universe full of ink marks. Great solar storms sometimes show when patience had run out, this was a real trial.
Examples for engravings were sometimes set up with black ink with charcoal, which could be transferred under pressure to a white waxed copper plate. Charcoal ink recipes include powdered charcoal, vinegar, salt, and gum arabic. For the print on a waxed copper plate, the binder will have been omitted. Bach's engraved scores give no indication that this technique, which was known to a few professionals, was used.
Soot ink does not acidify the paper and can be recognized quickly because the paper does not show any brown discolorations typical of gallus ink.
Some recipes for carbon black have been handed down, for example by Joseph Moxon and Martin Dominique Fertel.
The distinction between brown and black inks was not black and white. Pure inks were not the norm, everything was mixed up and alternated, inkwells were not thoroughly cleaned.
Rastrums were made of brass, an alloy of copper and zinc. Brass is easy to process due to its low hardness, which is also its weakness. The goal of rastrology, the science of comparing measurements between the lines of manuscripts, benefits from practical experience: it is an unstable tool, variations can follow each other quickly, so the results achievable by rastrology are not high are placed. Historical instructions like: "This pen may be used, but if it will not make good lines without bearing on too hard, it needs some repair", testify to its vulnerability.
We can recognize people by the way they used it. You can make the rastrum land like an airplane, glide through and make a go-around. You can also plant it down like a fork, plow through the field and put it down like a fence at the end and lift it up. You can skate like a first time ice skater, slide like a skilled snowboarder, or walk like a drunk. We can store a library of moves. Bach was an experienced pilot, careful, in control and confident.
We want the lines to have all the same thickness. A new rastrum can be uneven, especially the outer ones are regularly thicker. The position of the tines can also differ. Some calligraphers address this by bending and fine sanding. Sanding the nibs easily goes wrong, too much pressure will ruin the pen, and a wrong angle makes it to weak. Best practice is to first try it to align by using it, making a few pages without adjusting. Metal wear out round and rastrums can be sharpened with a whetstone - they should not become knives.
Metal writing pens have been around for several millennia. It was not for nothing that people preferred to write with a quill. In 1780 steel dip pens appeared for the first time, at the request of one who constantly bent his metal nib, before that they were made of softer metal, too soft to be able to use properly. A metal rastrum was a refined tool, learning to use it could be as strenuous as learning to play violin. It was so delicate that it was almost always a compromise and the scores show a lot of hand drawn restoring of incomplete lines.
There is a modern steel alternative, suitable to master quickly, strong and flexible. It takes away a lot of the stress that the weaker version causes, which feels like you're taking part in an unlucky lottery. From the steel alternative you can get results like you've been playing the fiddle for years. If you clamp a piece of sponge between the blades you can draw very long lines with it, but there are sufficient without it.
The antique French rastrum above has five equal nibs, which made five equal lines. We can see from Bach's use of a new rastrum that his tools looked like the first modern example. The outer nibs differ from the inner ones, they are a bit firmer, use ensured equal alignment. They are available in brass and steel, which makes a big difference.
There were double rastrums, to be able to draw two staff lines at a fixed distance at once. They need a broad inkwell. Bach did not use these. Small rastrums are not commonly available, but it is possible to edit a pen with a wide blade yourself.
Notepaper was often prepared in a stack, so there was in that case when used no planning of layout related to a composition.
Filling a page with staff lines is monotonous work that must be done nevertheless with attention, it is a craft. It is also a job that you can easily outsource to your children or students in your care.
Igor Stravinsky invented the Stravigor, a twentieth century tool in which five wheels roll along an ink pad.
No type of bird is wrong to use as a source for a quill. A feather that you find during a walk can do well, clean it, and you can get started. What works, works. It is so now and it was so in the past.
They do differ in hardness, a turkey feather is very soft, a seagull is very hard, the raven is refined, the goose wonderfully resilient and the swan full of strength. Old feathers harden, which makes them last longer, the quality does not deteriorate.
A raven feather is great for delicate work, but doesn't provide a firm grip. You might suspect that Bach alternated between goose and raven depending on what had to be written. I think that he mainly used goose, with which you can also make hair-fine lines when you tilt the tip, as is constantly needed for accidents, for example. Switching is a hassle and I imagine Bach doesn't do that except for text and sketches.
Goose and swan feel great in the hand, better than our modern writing instruments and are definitely one of the attractive sides of calligraphy. The five outer pins of a wing are most suitable. There is a lot on the internet about how to prepare a quill, you can check out a few, some of them are really excellent, and you can also forgo the pleasure of working with this wonderful material.
A part of a watch spring in the shaft increases the absorbency of ink, allowing you to write more with a dip. This was a common improvement, dating back centuries, and history doesn't stop you from using it.
Paintings show that writers always had their pen knife at hand. Feather tips were constantly trimmed. The knife had to be sharp, like his razorknife, so they had water and whetstone ready.
"Bach's music speaks with the tongues of angels of Lutheran Christianity, of malaise bound up with this type of Christianity and of the bitterness and spirit of self-sacrifice with which suffering can and must borne and endured. A good Christian, I learned, at a time of physical abstinence. Everything is forbidden, from parallel fifthts to polygamy, from clairvoyance to contact with people with different ideas. None of this, thank God, is found in the case of that man of God, Johann Sebastian Bach." - Hans Werner Henze
Bach's many voiced art is referential on many layers. A form might have been shaped by meanings on different structural layers. Charging a motiv with non explicit associations loads it with infinite connotations. Harken to Bach's tongue and intended and unintended blossoming appearing connections happen.
Friedrich broke the graphite, from Central European mines, sieved out sand grains and combined it with molten sulphur. The mixture was kneaded and dried and placed in a wooden case. These leads had good wear properties due to the sulfur binder, so they were as easy to write as pure English graphite.
The pencils are marked with sealing wax, hence the candle in daylight, chipped parts may have become part of Bach's scores.
They looked like modern carpenter's pencils which have two main properties: their oval shape prevents them from rolling and their graphite is strong - about gradation 2H. They can take a beating and the graphite pen does not break easily in the event of a fall.
Rubber erasers were invented in 1770 when an Englishman mistook a piece of rubber for bread, which doesn't plead for their bakers. Bread has long been used by artists to erase charcoal, it works excellently, and was also applied to pencil.
A perfume nebulizer could be used to apply fixating stale beer, sugar and proteins ensured adhesion. For the Great Complete Universal Olfactory Point of View we can register that it smelled like old beer because is was old beer. A potato was an odorless alternative.
After prehistoric times, the use of crayon again peaked at the beginning of the 18th century. So it is not surprising that we occasionally encounter a line or a word in crayon on Bach's scores, but it was not a meaningful nor systematic use.
Carl Philipp Emanuel wrote: "My father's portrait is painted in pastel. I had it transported here from Berlin by boat and ship because such paintings with dry colors can be damaged when transported by coach."
A relative of Bach: Gottlieb Friedrich Bach (1714-1785) was a painter and made pastel drawings at severall stays at the household of Wilhelm Friedemann, Carl Phillipp Emanuel and Johann Sebastian Bach. Pastel on paper is very powdery, by candlelight it glows and sparkles as giving light itself, a magical effect that is completely lost in digital reproduction.
Bach sometimes used a ruler to make straight bar lines. We can look at when he did so and presume why, search for ruler rules. Bach rules.
Bach had slightly limited eyesight.
In the painted portrait you can see vertical wrinkles coming from the bridge of the nose, as well as the squinted eyes. This squeezing has been termed by various experts as due to myopia. It is not a disease but a refractive error in the optical system of the eye. He could clearly see nearby objects.
Glasses could have corrected the anomaly, but were not widely used, and in Bach's case there is no record of them.
In the painting there is an excess of sagging eyelid skin and bags under the eyes due to fat. This has no serious consequences, except that the upper field of vision can sometimes be limited.
In his late years, we may be able to observe details associated with his health and sight. Like, for example, staff lines that descend to the right: BWV 232 Benedictus 1749. For a possible explanation we will have to look at the physical act of drawing straight staff lines with a free hand and see why it may deviate.