David Rawlings brings his 'Almanack' to Zellerbach Theatre on Thursday

David Rawlings is on the road, riding from Boston to Burlington, Va., toward a show at the venue Higher Ground. He's talking about the road — the highway he's on, but also his principled, painstaking way of crafting his recordings.

"That's the job, though," he's saying. "If you don't get it the way you like it, there's no point of setting down this road."

At 7:30 p.m. Thursday, "An Evening with David Rawlings" breaks out at the Zellerbach Theatre at Penn's Annenberg Center. He'll have quite an Americana all-star band: his frequent collaborator (and, yes, they're a couple, but they think talking about it is hokey) Gillian Welch; Paul Kowert, bass man for acid-bluegrass gods the Punch Brothers; Willie Watson, singer/guitarist/banjo plucker for Old Crow Medicine Show; and fiddler Brittany Haas. They'll be playing most of Rawlings' recent album, Poor David's Almanack, "plus we'll be mixing it up with all sorts of other stuff in there. Gillian will sing some, Willie Watson will sing some, and I'll do my usual madness."

A lot of people see Rawlings and Welch as curators and gatekeepers of the music known, spaciously, as Americana.

They are famous musicological Dumpster divers, haunting record stores, poring through the bins, questing for unknown gems and rarities. They also are famed for the exquisite taste of the recordings they have made, together and apart, for 21 years now. They care about this music, they choose carefully, they have mountainous standards, they sing and play like angels, and they are absolute studio rats, recording on analog tape because "it just sounds better, that's all," and then killing themselves to get the perfect sound. (See below.) Want to hear Americana at its best? Listen to Rawlings, Welch, and company.

As for Almanack, "I really wanted, on this batch of songs, so rooted in traditional melodies and traditional stories, to stay as close to the taproot of American music as we possibly could," Rawlings says. "I also really wanted the music to be the kind of thing you could either listen to very closely or enjoy when you were washing the dishes."

If you like your sound pristine, crackling alive, and authentic, listen to Almanack. There is good-time music, such as "Come on Over My House" and "Midnight Train," and humor, as in as "Money Is the Meat in the Coconut" and "Good God a Woman," in which the Creator realizes there's one more thing to be created. There's "Cumberland Gap," a dark, stomping tune in which Welch's harmonies with Rawlings recall Nicks and Buckingham, plus Crosby, Stills, Nash and Young's "Ohio."

There are even strings, as in "Airplane." Strings? "Well, yes," Rawlings says, "I wanted to try to do a more pop string treatment, just violins, a melody line by one whole section, and intertwine that with Brittany Haas' fiddle part. It was a challenge, but she plays with pitch and precision that lets you put violins under it. It was a real fun thing to buckle down for a few days and arrange that part."

Then he describes the hair-raising way he, Welch, and company created the master for the vinyl version of Almanack. "We used a Neumann VS82 lathe to cut the record directly, in real time, into a lacquer disc, like the old days," he says. "That meant we had five people manning different controls on the board as the lacquer spins and the clock ticks. It was very intense. We had about 30 percent chance of success. And you have to be able to make these incredible number of changes in the one or two seconds you have between songs." Somehow, they had a complete album in five tries. But, as he says, that's the job. He and Welch have returned to the master tapes of classic albums such as their 2003 Soul Journey  and her 2011 masterwork The Harrow & the Harvest, recutting them for vinyl. "I'm so pleased we've gone down this road," Rawlings says. "We're an independent company. We've done everything ourselves for two decades now."

Americana, folk, country, roots music … what, exactly, is that taproot Rawlings mentioned? "It's when you hear or think of a phrase or melody that seems like it has always existed, when you can't believe it didn't already exist. When you ask yourself, 'How did no one ever write this before?' You're just looking for things that make your heart feel that way. The truth is, with me, if Gillian's sitting in the studio, and she plays something, and I feel, 'Please, don't ever let her stop' — that's my compass. That's what you're after."

An Evening with David Rawlings. 7:30 p.m., Dec. 7. Zellerbach Theatre, Annenberg Center, University of Pennsylvania, 3680 Walnut Street. Tickets: $35-$42. Information:  215.898.3900, annenbergcenter.org