Mick Jagger has sent out a tweet that suggested that the Rolling Stones were planning to release an album of blues covers. Since then, we’ve uncovered a few clues, including some quotes from producer Don Was, who says that it might be out in time for Christmas and features guitar work from Eric Clapton on a pair of songs.

Jagger’s tweet featured a picture of a harmonica case that had a few Stones guitar picks thrown in. “Watch this space #playingtheblues,” he wrote.

Word that they had returned to their blues roots first surfaced in April, when Ron Wood leaked the news. “We went in to cut some new songs, which we did, but we got on a blues streak,” he said. “We cut 11 blues in two days. They are extremely great cover versions of Howlin’ Wolf and Little Walter, among other blues people. But they really sound authentic. When we heard them back after not hearing them for a couple of months, we were, ‘Who’s that? It’s you.’ It sounded so authentic.”

A few weeks later, Don Was gave a little bit more information on the project. He said that, in order to loosen up the band, Keith Richards suggested playing Little Walter’s “Blue and Lonesome.” “It was just magnificent,” Was told Australia’s RRR (the interview begins at roughly the 1:54:00 mark). “When they play that music, they become something very true to who they are and something really unique as well. …It’s really good.”

But he also noted that they weren’t sure when it would see the light of day, because they were committed to writing new songs.

Today, French outlet Le Figaro published an interview with Was. We used Google’s translator to determine what he said. "The album consists of covers of blues songs of Chicago,” he began. “It was recorded live in the studio in just three days, with the musicians in a circle around the microphones. There was no retouching on the pieces. Means the battery of Charlie Watts through the microphone of Mick Jagger [Editor’s note: this could be saying that the drums were bleeding into the vocal mic]. The record sounds very crude, very authentic. It captures the essence of what they are."

Was, who added that it was scheduled for a December release, also said that Clapton sat in on the sessions. "He was recording his own album in the studio next door,” he continued. “He had only to cross the hall to join! Hearing them play in the studio, he had also gasped. … He was still a teenager when he saw them in the clubs of Richmond in their infancy, as a fan. He borrowed one of Keith's guitars and started playing two songs. It was exceptional enough to see."

Finally, two weeks ago, Wood again spoke about it on the red carpet at the Toronto International Film Festival, where he and Richards were on hand to premiere Havana Moon, their documentary about their trip to Cuba. “It’s gonna be great,” he said in the video above. “You’re gonna love it. That’s what the Stones are: a blues band. Yeah!”

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