All About Pads: Part 1
The history and development of woodwind pads
One of the predominant features and points of discussion regarding woodwinds is the pads. What are woodwind pads? Why do we need them? Why is there such variety and so many choices?
History
Many many years ago, woodwind instrument had no keys. They only had holes that would be covered by the player’s fingers. The instruments at that time (18th century and earlier) were what were considered diatonic instruments. They played in the key and mode they were build to with few options for accidentals or key changes. If you were playing a piece written in C major (ionian mode) you played an instrument built in C. Of course this instrument could also be used to play in A minor (aeolian mode), but if you had a piece written in Bb you needed a whole new instrument.
Players began to approximate pitches not in the key signature by only covering half of a hole to create a pitch somewhat higher than the pitch it was supposed to be. Players would also use certain cross fingerings where, for example, a fingering of all fingers down on the left hand and the first finger down on the right hand (123|1xx) would give an F#, but adding the 3rd finger of the right hand (123|1x3) could give a passable F natural.
Instrument makers began adding extra holes at strategic positions that , when uncovered, would produce the “in between” pitches with more reliability and uniform timbre with the rest of the instrument. These new holes, the first of which is what we would identify as for an E-flat, needed a way to be covered and uncovered when the player needed it. This led to the the development of keys — spring actuated levers that the player could depress to uncover the new hole. Instrument makers had mostly been wood turners and wood carvers. Now they needed to learn or employ people with metal working skills.
But this fancy mechanical contrivance itself was not enough. There needed to be a way for the key to create a seal at least as good as a finger over a similar hole. Instrument makers of the time adhered a piece of pliable leather to the key to act as a gasket when closed against the tonehole. Early keys were simple paddles with a square shape on the tonehole end, so a square slab of leather of the proper thickness was adhered to it.
This design of a leather slab gasket was the first woodwind pad.
Pad Developments
From the early one-key instruments with one leather-clad extra key, more keys were added to facilitate more pitches leading to wind instruments that were functionally chromatic, meeting the needs of what the late baroque and classical composers of the time were writing. At this point, all of the padded keys were closed at rest. If they had been standing open, the leather would have lost its form which sealed against the tonehole. All standing open holes were still covered by fingertips.
In 1785 an English flute maker named Richard Potter obtained a patent for metal “valves” to cover the extra holes. Potter’s patented pewter plugs (sorry, couldn’t resist) were the first “improvement” on the leather slab pads. The conical shaped plugs were designed to fit into the tops of the toneholes and create a seal. We can’t really call these “pads” but the intended function of sealing the tonehole was the same.
In the first half of the 19th century two new improvements on the tonehole sealing gasket were developed. One of these developments emerged around 1810 from the clarinet maker Iwan Müller. He desired to make his clarinet fully chromatic and wanted to avoid the noise associated with the pewter plugs. His “pad” design was a circular piece of leather with a drawstring stitched around the edge and stuffed with wool fibers.
Müller’s pad design accompanied the prominence of “salt spoon keys” on woodwinds. Given the strong silversmithing component coming to the fore of instrument making, it is unlikely that these keys were actually repurposed salt spoons due to the ease of casting such shapes, but the form of them is aesthetically pleasing and Müller’s pad design, sometimes called purse pads or elastic balls, went hand in hand with these keys for many decades.
For more on this style of pad, visit Terry McGee’s research pages.
Around the same time the “elastic balls” were being used, instrument makers on the European continent were trying something else. Instead of loose wool, French, Flemish, and German instrument makers were using discs of felted wool. The felted wool could be regulated for thickness and density, providing a more consistent component. The concept of interchangeable parts was developed in the French military in the Napoleonic era and the benefits of those concepts spread through the industrializing world and even the artisan crafts. Why make each individual part bespoke for that one application if a consistent component of known dimensions could be made en masse and used more efficiently?
Felt is not air tight, so, as with Müller’s pad design and the slab pads before them, they also turned to thinly skived leather to wrap the porous felt disc. For the larger instruments leather worked well. Bassoons, ophicleides, and even Aldophe Sax’s improvements on the bass clarinet in the 1830’s made use of leather wrapped felted wool. This concept endures in the 21st century. But for smaller woodwinds leather was too bulky and unwieldy to give consistent results.
Fortunately, the new need for metals workers to make keys brought exposure to another material familiar to goldsmiths: goldbeater’s skin. Goldbeater’s skin is sometimes called fish skin, but it is made of neither fish nor goldbeaters. It is a membrane from a section of the digestive track of cattle and sheep and goldsmiths use it to separate pieces of gold that are to be beaten in to gold leaf.
This membrane or skin is very thin (around 0.001” thick) and is very durable. It provided the ideal qualities for wrapping felt discs for smaller woodwind instruments. It was common to have a backing piece of thick paper, card stock, or even wood to lend rigidity to the pad. Keys of the shape likely to have used (or in need of) such pads began to appear among French flute and oboe makers of the late 1820’s.
Many of these makers in the 1820’s were likely still using leather discs of precisely controlled thickness and firmness much of the time because of the durability. The goldbeater’s skin was very durable, but not nearly as durable as leather.
Then in the 1830’s the game changed. Theobald Boehm devised his 1832 system flute and Georg Wilhelm Triebert made improvements to oboe mechanisms which both required many more keys standing open. The precision required for these mechanisms could not be met by leather products, so card-backed felt disc pads wrapped in goldbeater’s skin became more prevalent.
By the late 1840’s, woodwind instrument makers were becoming more adventurous in making larger toneholes in instruments, holes that were too large to be covered by a human finger or positioned in a place unreachable by fingers. The pad technology of felt discs wrapped in some sort of animal product enabled many of these designs to succeed. A common term for this type of pad where an airtight skin covering of some sort is wrapped a cushion is bladder pad. This is the foundation of the woodwind pad technology we still see in use two centuries later.
To be continued…
At the Woodwindfixer’s Bench is a publication of Jeff’s Woodwind Shop, a woodwind repair shop in Baltimore, MD. To get in touch with Jeff, visit www.woodwindfixer.com.