It’s the classic scenario that you always hear about but hope never happens to you. You have an unorthodox, creative job that makes it hard to afford real health insurance -- or if you do have health insurance and get into a serious accident, you might be in just as big of a pinch. That’s the scenario that Laura Masura finds herself in. Luckily, she’s got big friends in high places, namely Billy Corgan and the Smashing Pumpkins. Corgan and his other band, The Backwards Clock Society, are headlining a benefit show on Sunday for Masura at Echoplex. (The band also includes Kerry Brown of Ancient Chinese Secrets and Mark Tulin of the Electric Prunes.) Additional performers include The Happy Stars (Brian Young from Fountains of Wayne), The Pulsars, Tim Rutili (Red Red Meat, Califone), Pity Party and Light FM. If you're a Pumpkins obsessive, a couple of goodies are being auctioned off, including Jimmy Chamberlin’s autographed drum kit used in Gish, and one of Corgan’s bass guitars. But how does one get Billy Corgan to play one's benefit show?