When Fleetwood Mac performed in Eddie Vedder's home state of Washington over the weekend, the Pearl Jam singer jammed with the band's newest members, former Heartbreaker Mike Campbell and Crowded House's Neil Finn.

But this musical summit didn't take place onstage. Instead, the collaboration happened in the most unlikely of places: the bathroom.

It was part of Campbell's new series "Bathroom Jams" that he posts to his newly created Instagram account. The guitarist shares snippets of himself, and sometimes guests, jamming in backstage bathrooms.

In one one recent installment, he referred to it as "tours of bathrooms of the United States." The Washington video marked the 15th video in the series, which started on Oct. 15.

You can watch it below.

In the short clip from Tacoma, Wash., Campbell shouts over the sounds of laughter and the three guitars, and callsFinn and Vedder his "brothers from another mother." Finn doesn't say much, playing with one foot up a toilet seat, while Vedder, donning a baseball cap, remains quiet and keeps his head down as he plays.

Campbell and Vedder have shared more than a bathroom stall. Vedder was an onstage guest of Tom Petty and the Heartbreakers on several occasions over the years. In 2012, Vedder appeared with the band in Amsterdam following the Isle of Wight Festival; in 2006, he hopped on stage with them in Denver.

Vedder has also been known to perform Petty's "I Won't Back Down," from 1989's Full Moon Fever, for audiences. Following Petty's death in 2017, Vedder performed a tribute to him at the Oscars this past year, playing the late singer's Echo song "Room at the Top."

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