Robert Plant and the Sensational Spaceshifters were in the midst of a hypnotic version of "Little Maggie" at Switzerland's Paleo Festival when a special guest bounded on stage. Joan Baez can be seen in the video above, at about the four minute mark, last night (July 25) in Nyon, Switzerland.

She wasn't there, however, to add any signature folk-tinged vocal – or even to segue into a duet on "Babe, I'm Gonna Leave You." Instead, we see a red scarf-wearing Baez taking part in a happy-go-lucky jig with the former Led Zeppelin frontman. Of course, the chipper "Little Maggie," a stand-out cover song from Plant's current release Lullaby and the Ceaseless Roar, is uniquely suited for this fun little aside.

Led Zeppelin fans will recall that it was Baez who brought the song "Babe, I'm Gonna Leave You" to wide notice. Her version of the track appeared on Joan Baez in Concert, Part 1 some seven years before it was featured on Led Zeppelin I. Baez and Plant were memorably honored at the Americana Music Association Awards in 2008, as well.

Baez was apparently side stage after finishing a set earlier in the day at the Paleo Festival. Plant and Baez continue their current live dates on Monday, July 27. He plays with the Sensational Spaceshifters at Theatre Romains de Fourviere in Lyon, France, while she is set to perform at the Castle Amphitheatre in Wiltz, Luzembourg.

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