Rapper Kool Keith of the Ultramagnetic MCs and, more recently, Dr. Octagon, has teamed up with the master of the vocoder, Roger Troutman, for two tracks on Keith's new album.

Troutman, the former leader of the '70s jazz funk outfit Zapp, was last seen in the video for Tupac Shakur and Dr. Dre's "California Love.

As we previously reported (see [article id="1428302"]"Keith Starts Work On New Record ..."[/article]), Keith is currently holed up in a studio on the outskirts of Philadelphia working on his first solo album, due out this fall.