The project, Bragg tells Billboard.com, is an outgrowth of Henry's biannual curation of a song cycle at the Ludwigsburger Sclossfestspiele in Germany, where Bragg first worked in tandem with Cash. "We had a great time singing together," Bragg tells Billboard.com, "and since then we've been plotting on trying to get into the studio together. We're all coming together in November."

Bragg says he and Cash are sending Henry "bits of songs...and trusting him to collate it into something we'll enjoy," though he expects that some songwriting will certainly be part of the sessions in Los Angeles. "I spend a lot of time on my own records in the driver's seat," Bragg notes, "so it will be nice to sit back in [Henry's]basement with his musicians and Rosanne and sort of chip in and...riff off what the band is doing and what Joe and Rose want to do."

Bragg says he had never met Cash before working together in Germany but considers her "a great songwriter, particularly the 'Black Cadillac' album she made that dealt with the death of her mother and father and stepmother. It's an incredibly powerful album. And she turned out to be a really whipsmart person and, of course, a great musician."

Bragg acknowledges that the project in some way parallels his two "Mermaid Avenue" albums with Wilco in 1998 and 2000 -- when they crafted new songs from unrecorded Woody Guthrie lyrics -- though he adds those sessions were not as acrimonious as has sometimes been reported.

"People always talk about the problems between me and Jeff Tweedy," Bragg notes. "There wasn't any problem except neither one of us had ever worked on a record in which somebody else had say in what the mix would sound like. But we worked our way through it, and since then I've been more relaxed about it. The  great breakthrough working with Wilco, for me, was how great it is to be in the studio with someone else who can bring ideas. On my subsequent two albums with the Blokes [2002's "England, Half-English" and 2008's "Mr. Love & Justice"] were very conducive to that."

Bragg kicks off a two-week U.S. tour on Sept. 5 at Seattle's Bumbershoot Festival. He's continuing work with his Jail House Guitars initiative in the U.K. (and is also helping the MC5's Wayne Kramer launch a U.S. version) and is also mixing the companion album to his theater project "Pressure Drop," which debuted in London this spring and, Bragg says, may be filmed in the near future.