Tomorrow, June 22nd, the 7th annual Bicycle Music Festival takes San Francisco by bike. It begins at noon in Golden Gate Park, then bikes will haul a live music stage through the city to arrive in the Mission District at 6 p.m. Entertainment–all free–will continue until 9 p.m. For pedal-power enthusiasts, this is a chance to see (and maybe participate in) a bike-powered concert. This year’s festival features a 14,000-watt PA system, the largest ever for the event. It’s part of Rock the Bike’s pedal-powered stage, in which humans power not only the amplifier, but also the lights, sound board, and more. According to the Bicycle Music Festival schedule, fifteen musical acts–plus activist Bill McKibben–will take the stage throughout the day.