Michelle Branch -- Rob Thomas, part two?

For the first single off his upcoming album, Shaman, Carlos Santana handpicked the songstress to flex her pipes, even though she didn't know she'd have the profile-elevating spot when she first signed on.

"I was approached a few months ago to go into the studio and sing a song [for Santana]," she said. "I found out later it's the first single. ... I'm telling you, it was a really amazing, amazing experience."

The single, "The Game of Love," is a departure from Branch's previous, more yearning vocal style. This time around, her delivery for the uplifting pop/rock song is decidedly more adult and knowing. Co-produced and co-written by ex-New Radicals frontman Gregg Alexander and producer Rick Nowels, the song includes sample lyrics such as, "It just takes a little bit of this, a little bit of that/ It started with a kiss, now we're up to bat/ A little bit of laughs, a little bit of pain/ It's all in the game of love, I'm telling you babe."

The video, which was shot three weeks ago with director Paul Fedor (Hoobastank), is evenly spliced between performance clips of both Santana and Branch and a narrative in which the camera follows the singer around the streets of Chicago as she observes people in love, according to a source on the set. Unlike Branch's video for "All You Wanted," she won't be playing dual roles as observer and observed. "She's schizo, that Michelle," joked a source close to the project. "But she's not watching herself this time, thank God."

Santana's "Smooth" duet partner, Rob Thomas, reunites with the guitarist as a guest songwriter on the star-studded record (see [article id="1452769"]"Carlos Santana Promises Guest-Packed, Vibrant New Album"[/article]). Also on board will be Dido, Wyclef Jean, members of Ozomatli, Placido Domingo and P.O.D. (see [article id="1456947"]"P.O.D. Record Track For Santana Album, Assemble Bonus DVD"[/article]), according to reps for Santana.

Shaman is due out October 22, while "The Game of Love" will be released to radio September 23.