Entirely Talia at OccupySF

Today, the concept of political musicians achieving commercial success might sound oxymoronic, and groups like Peter, Paul and Mary might seem a thing of the progressive past. "When I was coming up in the '70s, you could record for real companies," said Lockhart. "It was still capitalism but it wasn't this voracious. The record labels weren't into being monopolies, they were into having a niche."

Others pointed to a more fragmented, diffused political scene to explain the lack of politics on the radio. But many believe that music is just as integral in contemporary struggles as it was in the past, even if the audience it reaches is smaller and the format is more innovative.

"I think our younger generation is just as engaged in art for social change," said Talia Cooper, a 26-year-old Oaklander who performs original political songs at rallies. Some current Bay Area groups, such as the Brass Liberation Orchestra, consist mostly of younger musicians.

Cooper, who records under the name Entirely Talia, remembered going to long Occupy lectures at the beginning of the movement and watching the crowd become re-energized when she lead them in song.

"People go to demonstrations and passively listen to speakers. There's just so much listening people can do," said Occupella's Hali Hammer. "When they're singing, they're directly involved."

"I used to think it was cheesy for people to say that revolutions need art," Cooper said. "But if you think about what gets people to show up, it's the beautiful posters, or the flashmob with the dancers, or the singing."

Occupella meets Mondays from 5-6pm at the weekly "Tax the Rich" demo on Solano Avenue at Fresno Avenue, Berkeley.