Jack Johnson, the new rock band fronted by rapper Mos Def, is finishing up work on its Rawkus debut album, tentatively titled "Black Bastard." The group, which also includes Bad Brains guitarist Dr. Know, Living Colour bassist Doug Wimbish and drummer Will Calhoun, and Parliament/Funkadelic keyboardist Bernie Worrell, plans for an early fall release for the set, to be teased with a single this summer.

"In my estimation, there's a lot of rock bands sort of just fiddling with hip-hop, and a lot of hip-hop bands sort of fiddling with rock," Mos Def tells Billboard.com. " I don't want to fiddle, you know? I mean, I listen to Black Sabbath and Bad Brains and, you know, Fugazi and Pantera. I'm looking for something that is rocking along those lines, that's jus t got some teeth to it. I don't want to do something that's sugary or glamorous."

The group will play its biggest show to date next Saturday (April 28) at the Coachella Valley Music & Arts Festival in Indio, Calif. "I really have no point of reference for what that's going to be like," the artist says. "Being out in the desert, it will probably be a very surreal experience."

With a full-scale tour planned in support of the Jack Johnson album, Mos Def's free time may be at a premium in the coming months. But he says he is committed to a second album with Talib Kweli under the Black Star moniker, and is even planning additional non-hip-hop releases.

"You know what, I've been listening to Shuggie Otis for the past two or three weeks," he says. "I think I've got a great ballad album in me. After Jack Johnson, people may expect another album like that right away, and that may or may not happen."

As previously reported, Mos Def will join Jurassic 5 and Dilated Peoples for the Hip-Hop For Consciousness Benefit concert, set for May 12 in Los Angeles.