the prehistory of "jazz": a (long) speculation

[Dale Coye]

Just speculating in turn, but it seems to me that it's more likely that the
pre-history of jazz was not from the French and baseball, but from
entertainment and jazzbo (using the archives for dates--which are only approximate).  I
realize the cites don't support it strongly, but it seems likely that jazz
meaning "crazy" was being used more generally than has yet been found.

1. Jasper in late 19th c. meaning 'guy' or 'oddball' or 'country bumpkin'
2. r-less regions make the ending schwa
3. re-interpreted around the turn of the century as varying between schwa and
/o/-ending, reinforced by existence of 'bo' which DARE has from 1893 meaning
'buddy' and as a possible origin of "hobo"  from the same time.  So you could
say "Where you headed, bo?"     The cite for Jasbo in 1914 Illinois fits in
here.
4. In the early 20th c. jazzbo's meaning shifts from 'strange guy, bumpkin'
to the more specific meaning of a Charlie Chaplin-type performer of low-comedy
and slapstick.   It can be positive, negative or neutral.
5. It also refers to that type of shtick, or  more generally 'crazy, wild'.
1917
6. Its meaning extends to non-performance contexts (the auto rally) 1914-Los
Ang. I assume the use of it here means that it must have been used in the
performance sense at least by 1914 as well.
7. It is shortened in LA to "jazz" by at least one reporter referring to
slapstick in a negative way in 1917  "jazz comedy"
8. It is used by a ball player to refer to a wicked curve (crazy curve) 1912
9. It is applied by a sports writer in San Francisco to a team and to a
band's music associated with that team...as Gerald Cohen has determined 1914
10. Jasbo becomes a perjorative term only, perhaps influenced by Sambo, a
highly derogatory term for blacks.

Dale Coye
The College of NJ