If you haven't heard of Gnarls Barkley, you will soon. Earlier this month, the collaboration of DJ Dangermouse and Cee-Lo stepped into a brave new world with the psychedelic soul single "Crazy." The song made history as the first to reach No. 1 in sales based on downloads alone. The duo's album, St. Elsewhere, won't be available in the United States until May 9, but you can listen to the single at www.gnarlsbarkly.com, or even better download it for free as part of DJ Audio1's Rhymes and Beats Hiphop-cast No. 5. Along with playing a handful of weekly digital-radio shows, San Francisco's Audio1 regularly posts his gnarls-ly blends of old-school and up-and-coming artists for folks on the go.