Details about the Mick Jagger-Dave Stewart supergroup SuperHeavy have been released slowly and the first public introduction of the music was almost as cagey. Jagger, Stewart, soul singer Joss Stone, reggae artist Damian Marley and film composer A.R. Rahman gathered to speak about the making of the album after about half of it was played -- no song titles provided --  Thursday (June 30) afternoon at the Jim Henson Studios in Los Angeles. Their chat emphasized the unique nature of the project and the random way in which the music, a multi-cultural free-for-all at the start, came together.

They entered the studio with "ideas, a few guitar riffs and a few snippets of lyrics," Jagger told the small group assembled to hear the tracks. "It's not my usual sort of way of working. You always want to leave some room for improvisation, but you need to have something, some songs, when you walk into the studio.

"It evolved very quickly. We sat around with our little pads (writing). We did do a lot of jams but it's all coherent and arranged. We just wrote them quickly."

"I wasn't really familiar with everyone else's music before," Marley added, "but you observe how they work. It was a great experience."

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Stewart received gasps of amazement and then rolls of laughter when he said they recorded 29 songs in 10 days. "Some are an hour and 10 minutes long, some songs are 42 minutes long," he said. It total, he guessed there was more than 35 hours of music recorded, from which he and his engineer found the highlights that would work as the roots of songs. "We re-convened and then sort of made it into a shape and in the last year it fell into place," he said.

One of the seven tracks played Thursday was the first single "Miracle Worker," a video for which was shot Wednesday. While most of the tracks played mix and match elements from multiple cultures -- Indian film music, reggae, blues, soul music and a dose of "Sister Morphine" -- "Miracle Worker" is a straight reggae tune. (The album's concept, from the start, was to see what would happen if a band of musicians from different cultures composed and recorded together.)

"One Day One Night" has the strongest collage construction, a mix of electronic beats, Indian and Jamaican rhythms and the blues with Jagger singing about the life of a run-down man -- the cheap motel, the fuzzy picture on the TV set and the warm vodka. "You're Never Gonna Change" is the most Rolling Stones-like song of the batch, a tense acoustic-guitar-driven number sung with a street-smart swagger by Jagger. "Energy," with Marley rapping the verses, is an upbeat "Slumdog Millionaire"-style dance track and the track "SuperHeavy," too, has a distinct Indian flavor in the beats and, toward its conclusion, a cinematic string section.

Other, less obviously named cuts included a ballad sung by Stone and fascinating blend of a dub bass line and strings to create a compelling pop song. Jagger said the selections chosen are representative of the album.

"It's powerful," Stewart said after noting how he got the idea for SuperHeavy from hearing various sounds from off in the distance while in Jamaica. "I love musicians from all over the world, but never liked the term 'world music.' That sounds like people knitting with yogurt."

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After the event Stone said in a separate interview that they would wait to see the reaction to the album after it is released Sept. 20 before determining a next step for the band. Stone intends to tour the U.S. in early 2012 in support of her upcoming "LP1" and "by then, fingers crossed, if the world likes SuperHeavy, we'll do some shows."