Paul McCartney made a stop in Seattle last night (April 17), and naturally, he thought to invite former Nirvana bassist Krist Novoselic to make a special appearance during the concert.

Novoselic joined McCartney on stage for the Beatles' "White Album" classic “Helter Skelter.” Novoselic, of course, came in on bass and threw in some backing vocals for good measure. Check out a fan-shot video of the performance at the top.

McCartney and Novoselic have collaborated together several times before. McCartney fronted the surviving members of Nirvana -- Novoselic, Dave Grohl and Pat Smear -- at the 12-12-12 Sandy benefit concert and a 2012 episode of Saturday Night Live.

McCartney was just revealed as one of six legendary artists who will reportedly perform at a brand-new festival created by the makers of Coachella. He will tentatively appear on a roster that also boasts Bob Dylan, the Rolling Stones, Roger Waters, the Who and Neil Young. That tour de force is scheduled to go down in October in Indio, Calif.