Jay Sean Tears Up the Charts

The London-based singer's first U.S. single, ''Down'' (currently at No. 2 on Billboard's Hot 100), is a surprise dance-pop smash. ''It's nuts!'' he says. Jay Sean was already a major star across the pond when Lil Wayne became obsessed with a clip of his on YouTube and helped get him signed to Cash Money Records. ''The first time we met,'' Jay Sean recalls, ''he said, 'Yo, man, I love your vibe. Don't change.''' He's big in India, too, thanks in part to a cameo in the 2005 Bollywood film Kyaa Kool Hai Hum. ''Luckily, I starred as myself,'' he laughs.