Steve Earle says the next Joan Baez album, which he's producing, is "a really, really good record." Check that. "It's a f*ckin' great record, man," he tells Billboard.com.

According to Baez's Web site, she anticipates a "late summer/early fall release" for the album, which comes on the heels of the 50th anniversary of her first performances at Club 47 in Cambridge, Mass. A title has not yet been determined.

Baez and Earle worked on the album in Nashville in December and earlier this year, with a band that includes bluegrass veterans Tim O'Brien and Darryl Scott, Alison Krauss' brother Victor on bass and Kenny Malone on drums.

Earle describes the album as "very acoustic but not archaic. There are some really great songs that we started out with, and then I wrote some stuff especially for it. I'm embarrassed -- for about 30 seconds -- to say I've got three songs on it; one of them is 'Jericho Road,' which is on my last record (2007's Grammy-winning 'Washington Square Serenade')."

Earle says Baez has also recorded songs by Eliza Gilkyson, Patti Griffin and Thea Gilmore. "She's one of the great interpreters of songs alive on the planet," Earle says. "We started out with seven songs she brought to the table that she arrived at by hearing them. Some of them she'd already started performing, so we started out with songs she very much wanted to sing."

Baez is planning a March 27 "A Conversation with Joan Baez" anniversary show at Club 47 -- now the Passim Center -- followed by a March 28 performance at Boston's Sanders Theatre where Club Passim will present her with a lifetime achievement award. She also has spring U.S. dates beginning March 21st in Albany, N.Y.