Jazz is hot. Since last year's showing of Ken Burns' Jazz on public television, sales of jazz music have risen. Recordings by Diana Krall and Cassandra Wilson have broken through to popular radio station formats and a number of performers have been featured in high-profile magazines. When you get your morning coffee at Starbucks or the local gourmet café you are more likely to hear Billie Holiday or Stan Getz being played in the background than the Beatles or Grateful Dead. Yet, to th …