The 'Song Doctor' Is In

Not that the success was a surprise, given Rubin's record for producing critical and commercial hits -- particularly in 2005, when the sonic swami sandblasted the upper reaches of the charts and repainted them in all of his favorite colors. Gold and platinum, to be precise.

You may not have heard of Rick Rubin, but you've definitely heard Rick Rubin, whose variety-pack soundtrack has become inescapable. The mercurial master of many domains, from rap and metal to country and Top 40, Rubin is probably the only producer in pop music capable of restoring Diamond's relevance while also making the art-metal band System of a Down sound sublime. Twice.

Two System albums ("Mezmerize" and "Hypnotize") headbanged their way to No. 1 last year, and Rubin had a hand in five more albums that reached the Billboard Top 5, plus an eighth that narrowly missed the Top 10.

Few producers have that sort of success in a career, let alone a single year. And certainly none do it working with such a broad range of artists: Dubbed "the king of rap" two decades ago by the Village Voice, Rubin has traded up to "the most successful producer of any genre," according to Rolling Stone. (Whether most successful means most moneyed, though, is unclear. Asked later what his net worth is, Rubin says, through a publicist, "No idea.")

The scorecard doesn't lie. Rubin's hits last year also included Audioslave's hard-rock album "Out of Exile," which went to No. 1, and Weezer's alt-rocker "Make Believe," which hit No. 2. There were also the two albums Rubin executive-produced for the hip-swiveling Colombian pop star Shakira ("Fijacion Oral Vol. 1" and "Oral Fixation Vol. 2," both Top 5 U.S. entries), plus "The Legend of Johnny Cash," a country retrospective that included six songs produced by Rubin. The Cash collection reached No. 11.

There was so much success that Rubin sometimes employs the royal we in discussing it.

"It feels nice that all the work we've done over the last 10 years has built up to this point," he says. "It's a testament to hard work; we're really not fooling around."

He adds: "I'm just trying to make my favorite music. That's how I work; I just do things based on the way they feel to me. I want to be touched by the music I'm making. Luckily, other people have shared that response to my work over the years."

And here, by the way, is how Rubin responds to his own work: While Diamond's song "Oh Mary" plays, its producer is entranced, his eyes closed, his bearish body swaying as he sits on a couch, barefoot, legs folded in the lotus position. As the track reaches a crescendo and Diamond's portentous baritone soars over a swelling string arrangement, Rubin leans back, as though floored by the emotional power of the song.

And he strokes that beard vigorously.

It's great to be Rick Rubin!

The respect! The royalty checks! The Rolls-Royce! The painstakingly restored 1923 mansion perched above Sunset Strip! The weekend house up the coast! The assistant who can be summoned from the next room via BlackBerry when he's thirsty for a bottle of organic unsweetened iced passion-fruit green tea! Ah, trappings.