Emmylou Harris is going back to the roots of her famed Hot Band for her next project.

Harris tells Billboard.com that she and original Hot Band guitarist Rodney Crowell are working on a duets album with producer Brian Ahern, who first worked with Harrison on her major label solo debut, "Pieces of the Sky" in 1975.

"Rodney and I have known each other since 1974," Harris says. "At one point before the Hot Band, the Hot Band was me and Rodney sitting around with two acoustic guitars learning Don Gibson songs... It's kind of a thing we always said, 'We've got to do a duet record,' and he's been busy and I've been busy. But earlier this year I just decided that I wanted to do a record with him, and if we didn't book it and plan it and set aside some time, it would be something we'd get to the end of our lives and regret we'd never done it."

Harris says the album will feature "mainly covers," though the duo also considered some of the songs Crowell wrote for others but never recorded himself. "It's kind of a crazy quilt of material," says Harris, who prefers to keep song list specifics "under my hat" for the time being. She and Crowell are "pretty far along" on the recording but that "winter came and Brian got sick and then I got sick. Hopefully Rodney won't get sick so we can get back to it pretty soon."

As for touring to support the album, Harris says, "I'm sure we'll do something, but he's got his career and I've got mine, so I don't know what we'll be able to do for sure."

This year also marks the 25th anniversary of Harris' first "Trio" album with Linda Ronstadt and Dolly Parton. The Grammy Award-winning, chart-topping collaboration will be celebrated with a box set that will combine it and 1999's "Trio 2" as well as session outtakes that Harris says "might be a real nice surprise for people."

On top of all that she's continuing to tour in support of 2011's "Hard Bargain," which gave Harris her highest Billboard 200 debut (No. 18) ever and her best Country Albums debut (No. 3) since 1980's "Roses in the Snow." "I'm very happy with that record," says Harris, who wrote or co-wrote 11 of its 13 tracks. "I figured it was time to put on the writing hat, and I gave myself some time write -- really cleared my schedule and put my energy into writing. I think it shows. We perform a lot of songs from that album, and it's always good to have new material that you like to go with all the old stuff that I still, fortunately, like. It keeps you fresh."