Hi Krin -- good to see you on the net.  John Corbett, Steve Ellsworth and
I missed you in Syracuse.
 
> I call upon my colleagues in the ether for help with my research
> on jazz in the movies: I'm trying to locate the earliest American
> films with jazz-inflected background scores.  There is, of
> course, a problem in defining "jazz" here.
 
First to clarify: are you only interested in synch-sound film?  In other
words, would you consider "silent-era" films, surviving scores and/or cue
sheets?  If so, the definition of jazz has to be even more carefully
considered, since the term pre-1920 has different connotations.
 
Second, and assuming you are interested in post-1927 "talkies" -- can you
tell us why you are interested in extradiegetic music specifically?  I'm
sure we can find lots of diegetic jazz in 1940s and before, film noir
springs immediately to mind right?  But I assume that the "background
score" movies that you seek are interesting because jazz carries
connotations re: race, class, gender, sexuality, region, crime,
nightlife, promiscuity, etc.  And those "connotations" are due in part to
the "earlier" diegetic use of jazz in film.
 
As I've said elsewhere, the diegetic/extradiegetic distinction, when
applied to music, is a useful point of departure but quickly becomes
untenable.  We can all cite examples of music which first seems
extra-diegetic, which is eventually justified by a radio or phonograph
etc. diegetically.  Or the other way: a character turns on a radio, and
the tinny sound eventually gives way to a surround-sound mix.  In
musicals, obviously, the diegetic/extradiegetic distinction becomes very
fuzzy.  Or even in a film like CASABLANCA, where the Marseillaise scene
is underscored by the "extra-diegetic" soundtrack.
 
Anyway -- as Krin points out, it will be difficult to decide what counts
as "jazz-inflected."  I would also point out that it is difficult to
decide what counts as "extradiegetic" -- but that depends on the
project.  Krin, can you tell us more about what you are looking for?
 
Peter Feng