Wynonna Judd had a surprise up her sleeve when she and her band, the Big Noise, took the stage at their San Francisco tour stop on Thursday (Feb.6.) Founding member of the Grateful Dead Bob Weir joined Judd onstage for a number of tunes, including a bluesy rendition of "Why Not Me." Press play above to watch!

Judd took audiences all the way back to the beginning of her career when she performed "Why Not Me" -- the 1984 classic was an important early hit for Judd during her tenure in the Judds alongside her mom, Naomi. It was their second-ever No. 1 hit, and stayed at the top spot for two weeks.

The song had an extra layer of groove and grit during Judd's Thursday night stop on the stage of the historic Fillmore. Of course, Judd has grown and matured in the decades since the song's release; as a solo artist, she also veered away from mainstream country towards a more Americana-esque smorgasbord of different musical styles.

Judd wasn't the only musician funkifying up the performance, though: Weir sat in on guitar for the performance, adding some extra rock 'n' roll star power to the stage. He remained onstage for much of Judd's set, after initially coming out to perform three Grateful Dead covers: "Ramble on Rose," "Althea" and "Truckin.'"

Per Rolling Stone, Weir also assisted Judd and the Big Noise as they delivered performances of Judd's solo material, as well as a performance of the Dead's "Jack Straw."

The show's encore featured another surprise appearance, this time from singer-songwriter Cass McCombs. McCombs and Judd have previously worked together; in the fall of 2019, Judd released a song she'd written with McCombs.

See the Judds Through the Years