Last night, My Morning Jacket frontman Jim James opened up for Preservation Hall Jazz Band’s show at Sweetwater Music Hall in Mill Valley, CA, and venue proprietor Bob Weir stopped by to join James for several tunes during his set.

Weir joined James on stage for the final five songs of the set, all covers, starting with a rendition of Marvin Gaye’s “Mercy Mercy Me (The Ecology)” followed by Daniel Lanois’ “The Maker.” Then the duo dove into a couple of Grateful Dead classics, “Brown Eyed Women” and “Candyman,” which had James taking lead on vocals and Weir backing him up and even throwing in a slide guitar solo in the middle. James recorded the tune for The National’s Day of the Dead tribute album. Watch a video of that collaboration above. The set was then wrapped up with the two musicians collaborating on Bob Dylan’s “Blowin’ in the Wind.”

Next up for both Weir and James is a stop at today’s Sound Summit, were Weir will team up with Phil Lesh & Friends.