For six years Phil Rosenthal pursued his rock-'n'-roll dream without much reward. He moved to Los Angeles. He started a Beatlesesque pop band, Twenty Cent Crush, and signed with the tiny label Not Lame Records. He cut a single, Sunday Girl, that was a hit in Finland, of all places. Stateside, however, his band was nowhere.
Then last August, Rosenthal met Joe Seta and Nora Rothrock, proprietors of a site on the World Wide Web called Artists Underground www.aumusic.com) who invited the band to post a sound clip on their Website and participate in a live "computercast" concert. In...