Little did Rod Stewart know what he was starting when he fulfilled a longtime dream by releasing the standards album "It Had to Be You ... The Great American Songbook."

Little did Rod Stewart know what he was starting when he fulfilled a longtime dream by releasing the standards album "It Had to Be You ... The Great American Songbook." The 2002 release -- which has sold 2.9 million copies in the United States, according to Nielsen SoundScan -- spawned a legion of copycat projects by other veteran artists, and brought Stewart back to sales levels he had not experienced in nearly a decade.

Each subsequent year has brought a new standards set from Stewart; this week, J Records will release "Thanks for the Memory ... The Great American Songbook Vol. IV." Produced by Steve Tyrell and BMG U.S. chairman/CEO Clive Davis, the new set finds Stewart dueting with Elton John on a campy version of "Makin' Whoopee," Chaka Khan on "You Send Me" and Diana Ross on "I've Got a Crush on You."

"We had a few arguments, Steve and myself and Clive, but they're nice battles," Stewart reveals. "They're those creative battles that you know if we have them, we're going to finish off with something magical. We wanted to broaden our horizons a little bit and bring in backing vocals and more guitar instead of the intro being on the piano. So we tried to expand a little bit. We brought in some horn sections. A few things are different, but basically it's just a notch up from the first 'American Songbook.' I think I'm singing them with so much confidence now."