The first time Zachary Hanson saw his own face on MTV, his reaction was a little different than that of most rock stars. "I said, 'Look at the cute girl--no, wait, it's me!'" says Zachary, a cherubic 11-year-old who won't need a shave until the next millennium.
Zachary's only joking, but his humor highlights the youthful blush that makes the trio Hanson stand out. After pushing waves of twentysomething alternative rock bands in the early '90s, some record companies are turning to even younger groups. "People are coming back to music that's fun and upbeat, and younger artists are filling that...