Jazz Unlimited host Dennis Owsley wrote the book on St. Louis jazz. No, really: Owsley's 2006 tome City of Gabriels: The History of Jazz in St. Louis, 1895-1973 is the first comprehensive, book-length history of jazz music in St. Louis. Owsley's erudition on musical matters local, national and international informs his radio show, too. Often building broadcasts around a specific theme, Owsley not only plays choice tracks, but also provides context that helps listeners put what they're hearing into perspective. That's not to say Jazz Unlimited is some kind of dry history lesson. Au contraire: Owsley knows it's the music that matters, and on KWMU (90.7 FM) from 9 p.m. till midnight on Sundays, he provides a consistently captivating presentation of the best jazz music of the past half-century.