Take two talented musicians (one studying to be a doctor, the other a psychologist), put them together, and you have a future in medicine that was best derailed. Ten years and six albums later, AmpLive (who has remixed music from Linkin Park, MGMT, and Radiohead) and Zumbi of Oakland duo Zion I have proven unstoppable.

The two rule the underground hip-hop scene and have worked with heavy hitters such as Aesop Rock, Mos Def, Talib Kweli and Gift of Gab. They started their own record label and have amassed an audience both here and abroad. “It’s not like a huge pop-based following, but the people who feel us are really into it,” says Zumbi.

With influences as diverse as John Coltrane and Bassnectar, Zion I’s sound runs the gamut from hip-hop to reggae to electro funk. Their infectious combination of socially conscious lyrics, live instrumentation, and sampling attracts fans across a broad spectrum. “I grew up listening to all kinds of music,” says AmpLive. “A lot of rock, a lot of electronic.”

Currently on a 40-city tour, the two are finishing their seventh album—due out this month—and are starting work on their second collaboration with local rapper The Grouch. Zumbi’s hip-hop album with the ARE and AmpLive’s first instrumental album are scheduled for release this year. All in a day’s work, says AmpLive. “We just keep putting out music.”