To be taken with a pinch of salt (looks like a great read, though, such a character):
'Orleans musicians were always looking for novelty effects to attract the public, and many of the most important things in jazz originated in some guy's crazy idea that we tried out for a laugh or just to surprise the folks.
Most people don't understand the novelty side of jazz. Vibrato-which is all right for one instrument but the worst thing that ever happened when a whole bunch of instruments use it-was nothing at the beginning but an imitation of a jackass hollering. There were many other imitations of animal sounds we used-such as the wah-wahs on trumpets and trombones.
Mutes came in with King Oliver, who first just stuck bottles into his trumpet so he could play softer, but then began to use all sorts of mutes to give his instrument a different flavor. And I, myself, by accident, discovered the swats on drums. Out in Los Angeles I had a drummer that hit his snares so loud that one night I gave him a couple of fly swatters for a gag. This drummer fell in with the joke and used them, but they worked so smooth he kept right on using them. So we have "the swats" today-a nice soft way to keep your rhythm going.'
Mister Jelly Roll: the fortunes of Jelly Roll Morton By Alan Lomax
Taken from a series of interviews conducted by Lomax, which are available as a CD box set (IIR).
The novelty thing rings true and Morton, despite being a bragger, had an annoying habit of being able to back up a lot of his claims...there was usually a grain of truth to them. However, more likely, if you ask me, that the tradition started in New Orleans during the teens of the last century. I've come across a few throw-away remarks to that effect in drum method books, but nothing to back them up.
Some interesting stuff coming up...well, if you're a brush-nerd like me! (stay tuned)