Paul von Janko, in the 1880s, proposed a technical standardisation that could make life far simpler for vast numbers of musicians, but it did not gain popularity. What was it?
A piano keyboard with multiple rows of keys (almost more typewriter-style) each arranged in whole-tone scales, so all tonal keys would feel the same shape under the player's hands (and no more all-different scale fingerings, for instance)
Music staves running down the page instead of across, so that the 'rhythm axis' ran vertically and the 'pitch axis' left-to-right in keeping with the keys on a piano. The system was named Klavarskribo ('keyboard script'), and publicised, using the then-also-new planned international language, Esperanto
Janko realised it was somewhat perverse that in standard Western musical notation, the shorter a note lasts, the more ink is required to indicate this (a demi-semi-quaver has three tails; a semibreve, lasting over 30 times as long, doesn't even have a stem). He accordingly proposed an inverse scheme which would make music less cluttered on the eye while also saving space and expense for publishers, buyers and players alike
He invented the letter-notation system known as Tonic Sol-Fa