Split sharp

A split sharp is a kind of <a href="/facts/Key_(instrument)/bQykdaCd">key</a> found in some early <a href="/facts/Keyboard_instrument/zVUA9QNG">keyboard instruments</a>, such as the <a href="/facts/Harpsichord/8RtW7bzM">harpsichord</a>, <a href="/facts/Clavichord/v0hAns7B">clavichord</a>, or <a href="/facts/Organ_(music)/QjxVlXU5">organ</a>. It is a musical key divided in two, with separately depressible front and back sections, each sounding its own <a href="/facts/Pitch_(music)/fQAK0JsC">pitch</a>. The particular keys that were split were those that play the sharps and flats on the standard <a href="/facts/Musical_keyboard/Mz0FGAe4">musical keyboard</a> (the "<a href="/facts/Piano_keys/lRI60lQK">black keys</a>" on a modern piano).

<blockquote>Split sharp. A sharp key divided or 'split' into two parts: the front part is about one third the length of the whole. Usually the back part is set slightly higher to facilitate playing. Each part has its own [parts] so that two notes are available. In Italian instruments it was common...to provide split sharps for e♭/d♯ and g♯/a♭. The usual practice was to put on the front part the note that would normally be found there, e.g. e♭ and g♯.</blockquote>
Split sharps served two distinct purposes. First, in the <a href="/facts/Broken_octave/vwq98Wt1">broken octave</a>, they allowed an instrument to include deep <a href="/facts/Bass_(sound)/3NpVU9Rc">bass</a> notes while retaining a short, compact keyboard.
Second, in older music, <a href="/facts/Musical_tuning/v5Q1kYxC">tuning</a> was generally not done by <a href="/facts/Equal_temperament/8AwSblW3">equal temperament</a>, which treats note pairs such as A♯ and B♭ as the <a href="/facts/Enharmonic/lSwDb7JN">same pitch</a>. Instead, they were assigned slightly different pitches on <a href="/facts/Enharmonic_keyboard/5WwY7Bkd">enharmonic keyboards</a> (particularly in "<a href="/facts/Meantone_temperament/bVoQDGQs">meantone temperament</a>"). This allowed certain <a href="/facts/Interval_(music)/aFwkkgpY">musical intervals</a>, such as the <a href="/facts/Major_third/7CPRURg4">major third</a>, to sound closer to their ideal <a href="/facts/Just_intonation/TM91PueU">just</a> value, hence more closely tuned to <a href="/facts/Just_intonation/TM91PueU">just intonation</a>.
Split sharps present advantages and disadvantages: "Obviously this would have its advantages under some circumstances in terms of intonation. However, the complexities of <a href="/facts/Fingering_(music)/PHoJwUeY">fingering</a> and hand position dictated by such a keyboard configuration presented problems." Specifically: "Such devices were obviously an impediment to rapid scale work in the lowest bass register, but this does not matter greatly as Italian seventeenth-century music generally avoids writing of this kind."
In modern usage, split sharps are usually the method of choice for custom keyboards that play <a href="/facts/19_equal_temperament/RWw5bQLP">19 equal temperament</a>, which, like meantone, uses different pitches for sharps and flats that are enharmonic in the standard 12 tone.

Split sharp open-in-new

Split sharp