NEW YORK (AP) 212; So far, Adele's "21" is the best-selling album of the year, with a little over 2.5 million copies sold. Rick Rubin, who produced several tracks on the album, says while he had no idea the album would connect with so many people, he understands why it has.

"She doesn't carry any of the baggage of many of today's pop stars, and it truly is about the music first, and her voice and her lyrics, and baring her soul with what she's saying. I would say what she makes is her art, and at no time does it feel like product," he said in a phone interview recently. "So much of pop music feels like product."

The British singer won Grammys for her debut album "19," but has catapulted to superstar status with the success of "21" and hits like the No. 1 "Rolling in the Deep." Figures released by Nielsen SoundScan earlier this week showed it was the year's most popular album at the mid-way point.

Rubin says the raw emotions in songs on the album, inspired mostly by the 23-year-old's breakup with a boyfriend, are what people are responding to.

"She really bared her soul lyrically, and I think that's what resonating with people — the truth in her lyrics, and the passion in which she tells that truth," he said.

Rubin, a Grammy-winning producer who's worked with artists ranging from Jay-Z to Johnny Cash to Neil Diamond, has several other high-profile projects he's working on, including albums from Metallica, Linkin Park, the Avett Brothers and the Red Hot Chili Peppers.

Rubin describes the Chili Peppers' album "I'm With You," due out Aug. 30, as unlike anything the band has ever done — but unmistakably Peppers music. He credits that in part to guitarist Josh Klinghoffer, who replaced John Frusciante, and personal changes group members have gone through since putting out their last album five years ago.

"Anthony (Kiedis) and Flea had children during that time, so their lives have changed a lot since the last album we made, and because they had taken this time off, they came back with a real hunger and excitement about the music-making process again," Rubin said.

"I think it's the first time in their career that they'd ever taken off that big of a chunk of time, and they've been a band for 28 years now," he said. "It really feels like starting all over again, because they have the dynamics of a new band."

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