As we were just saying: You never know what you're going to get at a Foo Fighters concert these days.

Just two days after welcoming Yes singer Jon Davison onstage for a cover of Rush's "Tom Sawyer," the Foos made room during their stop in Los Angeles last night for a cover of Stevie Nicks and Tom Petty's "Stop Draggin' My Heart Around" featuring guest vocals from Nicks and Haim.

As Nicks and Haim fans no doubt recall, this isn't the first time the Fleetwood Mac legend has collaborated with the sister trio; last year, they got together for a performance of "Rhiannon" and a joint Q&A session about life as a woman in the music business. As you can see in the fan-shot footage above, Nicks and the Haims clearly relish the opportunity to work together.

The magnitude of the occasion wasn't lost on the members of Haim, who posted an Instagram photo of the "magic scarf" they got from Nicks, and took to Twitter to let fans know they "died onstage" with Nicks and the Foos:

Originally a hit from Nicks' 1981 solo debut Bella Donna, "Stop Draggin' My Heart Around" was a duet with Petty, who co-wrote the song with frequent collaborator Mike Campbell and co-produced the Top 5 pop hit with Jimmy Iovine. It was one of several songs Nicks and Petty performed together during the early '80s — a list that also includes "Insider," from Petty's Hard Promises album the same year, as well as "I Will Run to You," from Nicks' 1983 effort The Wild Heart.

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