The small book Music as she is Wrote is a ‘glossary of musical terms very much up to date by the composer and conductor Frederic H. Cowen.’ It was published c.1915, however this has not dated the humour. I give four short definitions from it below.
A display of musical fireworks, introduced into a song by a prima donna to show the public that she possesses ever so many good (or bad) high notes that she has not had a chance of singing in the song itself. In a Concerto the cadenza is often nearly as long as the whole piece, but it has the advantage of giving the conductor a well-earned rest.
A short unaccompanied piece of vocal music in several parts, which begins in one key and usually ends half a tone or more lower.
A succession of notes used to fill up a bar in a composition when the composer has exhausted every other device he can think of.
An obsolete term.