One of the myths of jazz is that the raw material on which improvisation was based was dreck, and that jazz musicians took a largely hostile attitude toward this raw material (the popular songs of the day.)

Well, actually, no. These are great songs for the most part. And my hypothesis is that musicicans chose songs that they liked over those that they didn't like. Hence the huge preference among jazz musicians for the big four of Gershwin, Porter, Arlen, and Rodgers.

Take the example of John Coltrane playing "My Favorite Things." We know this melody is by Richard Rodgers, from the "Sound of Music." What is the more parsimonious interpretation? That Coltrane played this song in order to mount an attack on Richard Rodgers, or that he played it because he loved the song? Or take Monk's preferennce for Gershwin's "Nice Work." Monk only played a few standards, and he liked to play them over and over.

I think these Russian Jews who created Tin Pan Alley Americana were on to something great and that the black jazz musicians resonated with their creations. And what about Russian Jewish musicans like Stan Getz? Or Hungarian Jews like Benny Goodman? I don't think you can understand American popular culture without getting this fusion of Eastern European and African-American influences in the 1920s.