Bob Dylan turns 78 on Friday, but at KPFA we’re not waiting to celebrate his birthday. On Wednesday (May 22) Larry Kelp hosts a two-hour “Sing Out” Bob Dylan special from 10 p.m.-midnight. Since 1991 the “Bob’s Birthday Special” has been an almost annual event on KPFA. Dylan is a unique force in modern music, seemingly unstoppable and ever-changing, adding a Nobel Prize and a line of Heaven’s Door whiskey to his overcrowded mantle. After recent recordings of jazz and pop standards (crooning a la Sinatra), due in June is a massive 14-CD box set of his 1975 Rolling Thunder Revue concerts. Meanwhile, some of his strongest political songs of the ‘60s continue to be updated in struggles for freedom and justice. “Sing Out” mixes Dylan favorites and rarities with interpretations by a global array of musicians. As you tune in, remember: “Don’t follow leaders /Watch the parkin’ meters.”