You’ve heard songs from this genre—if you’ve watched enough TV or old movies, you could probably hum at least a few (think Dragnet, Shaft or Mission: Impossible). But although crime and spy jazz produced iconic melodies, says Davis writer Derrick Bang, these days the style is largely dormant. Bang has written two new books, “Crime and Spy Jazz on Screen” (they cover 1950-70 and 1971-present), to help bring the music out of the shadows. On today's show we define crime jazz, talk about the way it draws your attention, sample two of its popular songs, and learn the value of a killer opening theme—and why the style faded. The movie Easy Rider was a factor, as was the growing number of commercials on TV.