There's a radio station in Phoenix that plays nothing but vocal jazz (except Take 5, by Dave Brubeck, which they played twice in the week I was there. Odd because it is the only non-vocal piece they played. They do venture into new "pop" songs (e.g., they are playing Joss Stone right now). But they mainly play big band jazz vocal standards.
Anway, you can listen to them on-line:
http://www.star975fm.com/