In 1972 the musical prodigy Frank Zappa released two amazing records with two amazing title cuts. Both feature large ensembles with a big jazz band sound. This is some of the best jazz/rock fusion you’ll ever hear! Waka/Jawaka (listen) begins with an aggressive (triumphant!) brass anthem that still amazes me every time I listen to it. My favorite! The Grand Wazoo (listen) has a more laid back introduction, then proceeds through a series of jazzy improvisations. After several other notable cuts the album concludes with Blessed Relief (listen), a perfect anodyne. These albums were preceded by Hot Rats, which is a classic in its own right. It includes Peaches En Regalia (listen), probably the most famous instrumental number Zappa produced in his long, diverse career.
2009 Update: All my original links to music on YouTube have gone bad. I’ve compromised with links to 30 second samples on the Amazon site. Be aware that the Grand Wazoo sample is not representative of the track.