Following an enormously successful album series in which he covered classics from the 'Great American Songbook,' Rod Stewart is digging even deeper into his pockets for a new collection of soul tunes entitled, appropriately, 'Soulbook.' The album's 13 tracks include covers of timeless gems from Sam Cooke, Stevie Wonder, the Temptations and the like. But as with all of Stewart's new recordings these days, he's the singer, not the songwriter. Granted, he's covering some of the greatest songs ever written, but one could argue that Stewart's originals belong right there in that lineage. Surprisingly, the man himself disagrees.

"Songwriting was never something that came naturally to me," Stewart tells Spinner. "I can't imagine that I'll ever put pen to paper ever again. I'm having too much fun doing these."

Indeed, Stewart's taken a respectfully playful approach to these revered classics, sprucing some of them up with additional vocals by modern artists like Mary J. Blige and Jennifer Hudson. And he doesn't plan on slowing down anytime soon. "I've been enjoying recording these albums, these 'concept' albums, for wont of a better word," he says. "I could go on and on and on. I want to do a blues album, a country album. I've got 50 'American Songbook' songs already recorded."

'Soulbook' is in stores now, and if it gets a reception anything like its 'Songbook' predecessors, expect sales in the tens of millions. Yes, even in 2009.