Several months ago, Billboard reported on rumors that John Mayer would be joining some of the Grateful Dead members for a possible fall tour. While this was never confirmed, it seems all the more likely after Mayer joined Phil Lesh & Friends for their 1977 show tribute at Terrapin Crossroads in San Rafael, CA last night.

Bob Weir Can’t Discuss John Mayer Collaboration At This Time

Phil Lesh has been paying tribute to every year in the Dead’s career, starting with 1965, and last night he honored one of the more memorable shows, Cornell ’77 (5/8/77). When the plans were initially announced, there was no mention of the show selection or of Mayer. His performance was a surprise, but Mayer stuck around for the entirety of the performance, only playing lead guitar (and not singing).

The full band included guitarists Stu Allen and Scott Metzger, keyboardist Scott Guberman, drummers Pete Lavezzoli and Alex Koford and vocalist Jeannette Ferber. Phil & Friends will be back at it tonight for a second tribute to 1977 as well, and there’s no indication whether Mayer will be joining in the mix again. You can watch footage of the show below:

Phil Lesh & Friends w/ John Mayer – Terrapin Crossroads – San Rafael, CA – 6/12/15

[Video: Samwise Gamgee]

Setlist: Phil Lesh & Friends | Terrapin Crossroads | San Rafael, CA | 6/12/15

Set One: New Minglewood Blues, Loser, El Paso, They Love Each Other, Jack Straw, Deal, Lazy Lightnin’, Supplication, Brown Eyed Women, Mama Tried, Row Jimmy, Dancin’ in the Streets

Set Two: Scarlet Begonias > Fire on the Mountain, Estimated Prophet, St. Stephen > Not Fade Away > St. Stephen, Morning Dew

Encore: One More Saturday Night