>Has anyone ever heard of slimming down the sharp keys to better >accomodate pianists with "fat" fingers?... >Tom Robinson... Del Fandrich offered some fascinating information* back in 1998 on the newsgroup rec.music.makers.piano that I saved for such moments as this. Cudos to you, Del, for taking the time! Keith McGavern Registered Piano Technician Oklahoma Chapter 731 Piano Technicians Guild USA ================================================== * Date: Tue, 29 Sep 1998 10:39:11 -0700 From: Delwin D Fandrich <pianobuilders@olynet.com> Newsgroups: rec.music.makers.piano Subject: Piano Key Headscales ...It is quite true, the spacing between the sharps on the piano keyboard does vary...It is the result of the asymmetrical nature of the piano keyboard headscale... >From a piano builders perspective the octave starts at C and goes through B. In this octave there are seven naturals and five sharps. The sharps are laid out in two separate groups (C# & D# and F#, G# & A#). There is one natural key between each of these sharps. However, there are two naturals between D# and F# and another two naturals between A# and C#. With this layout you come up with two separate 'groups' of keys: C through E (with 5 keys, 3 naturals and 2 sharps) and F through B (with 7 keys, 4 naturals and 3 sharps). These two groups must be arranged in a manner that the human fingers can reach all of them without too much trouble. And, of course, there is this unfortunate requirement that the naturals all be of the same width. So an arrangement has evolved that does accommodate the requirements of the music, the human hand and the human eye. The width of the typical sharp is approximately 11.0 to 11.5 mm. More on some keysets but usually it is fairly close to 11.0 mm. (There is also a gap of approximately 1.5 to 1.6 mm on either side of each key -- this is the width of the bandsaw blade used to cut the keys apart, plus a bit for sanding to make them look pretty.) Over the years it has been found that there needs to be a minimum gap of about 15 to 16 mm between the sharps to allow space for the various sizes and shapes of human fingers. More would be nice, but to get more space between F# & G# and between G# & A# would require moving F# further to the left and moving A# further to the right. This would make the tail -- the tail is the visible portion of the natural key that is located between the sharps -- of the F and B keysticks even thinner than they already are. There does need to be some minimum width to maintain adequate key strength and stiffness. The width of the F and B tails are usually around 11.5 to 12 mm. Much less would be stretching the limits of both key strength and stiffness. For esthetic reasons it is common to try to make the width of the key tails as uniform as possible. In most keysets this means that the width of the B & F tails are usually held to a minimum of approximately 11.5 to 12.0 mm and the E & C tails are a maximum of approximately 13.0 mm. They are not identical, but they are close enough so that they do not look awkward. This leaves only the tail of D as the oddball. It is usually about 14.5 mm wide. C# and D# could be moved closer together but then the tails of C and E would be even wider, upsetting the visual balance of the keyset. Since the eye compares the gap between C# and D# with the gaps between A# & C# and D# & F# the wider space between C# and D# does not look out of place.... Regards, Del Delwin D Fandrich Piano Designer & Builder Hoquiam, Washington USA ==================================================
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