About 30 minutes into every concert on the Black Eyed Peas' current tour, band leader will.i.am performs a freestyle rap, riffing on text messages sent by audience members. It's a flashy solo turn for the musician who has steered the group since 1995. It's also a moment in the spotlight for the tour's primary sponsor, BlackBerry, which delivers the messages scrolling up two huge screens on the stage.

On its path from rootsy L.A. hip-hop troupe to pop juggernaut, the Black Eyed Peas have been escorted by a parade of corporate backers. From Coors to Levi's, Honda to Apple, Verizon to Pepsi, brands have padded the group's video budgets, underwritten its tours and billboarded band members in prominent places. When Apple was preparing the 2003 launch of the iTunes store, The Peas' "Hey Mama" became the first song associated with the iconic campaign's dancing silhouettes, a point of pride for will.i.am, the band's frontman.

For the musician, wooing potential corporate partners has become as integral to his job as the DJ sets he does on tour at after-parties sponsored by Bacardi. Often will.i.am pitches the concepts himself using "decks" that sum up the Peas' package, frequently in PowerPoint form.

"I consider us a brand. A brand always has stylized decks, from colors to fonts. Here's our demographic. Here's the reach. Here's the potential. Here's how the consumer will benefit from the collaboration."

If will.i.am wasn't in music, "He'd be the best ad executive on Madison Avenue," says Randy Phillips, president and CEO of the concert promoter AEG Live. "I've never seen anyone more astute at dealing with sponsors' and companies' needs and understanding their brands." He says he's planning to have the rapper deliver a seminar to AEG's global marketing team.