Now in its 40th year, this Oakland group has become an institution. With a huge horn section and deep grooves, the Tower of Power sound is one of the most recognizable around. In their stage shows, they segue easily from funk to smooth jazz to blue-eyed soul. This ability to cross genres has brought them innumerable recording opportunities with widely diverse artists; few ensembles can claim to have recorded with Lyle Lovett and Aerosmith, but that's hardly a stretch for these men in black. Like their most famous single, these virtuosos seem to always know “What Is Hip,” and they keep refining it.