It's time once again for the Northwestern University Music Marathon. This beloved Chicago-area institution begins at 8PM on April 30 and delivers what the organizers describe as "twenty-six hours of awesome." The schedule will feature, as it did last year, a wee-small-hours rendition of Terry Riley's In C by Billy Robin's Hep Cats, an ad-hoc group whose name seems inspired by Toscanini's Hep Cats, aka the New Friends of Rhythm. All proceeds will go to the People's Music School, which provides music instruction to Chicago-area kids free of charge. Billy Robin, a sometime contributor to Noise-dot-com, blogs here.