Widespread Panic headlined Quincy, CA’s High Sierra Music Festival for the first time since 1999 Friday night. The jam-titan’s High Sierra performance was part of the festival’s 20th anniversary celebration. As expected, Panic invited out several additional festival performers during its two-set performance. Guitarist Eric McFadden, who plays in Dave Schools’ Stockholm Syndrome project, emerged partway through the group’s second set for “Bowlegged Woman.” As the song segued into “Light Is Like Water,” McFadden was replaced by two additional members of Stockholm Syndrome: guitarist/vocalist Jerry Joseph and percussionist Wally Ingram. The latter musician reemerged later in Panic’s set for a run from “Drums” into “Surprise Valley.” In addition, Karl Denson played saxophone on “Ride Me High.” Jerry Joseph actually played the very first High Sierra with his seminal group Little Women.

High Sierra’s other marquee name was the Black Crowes. The veteran southern rock band played an extended set as part of its farewell tour that included radio favorites like “Soul Singing,” “Hard To Handle” and “Remedy.” One of the jamband circuit’s longest running festivals, High Sierra also boasted performances by the likes of he Avett Brothers Ozomatli, Femi Kuti and Positive Force, Railroad Earth, Bela Fleck, Zakir Hussain, and Edgar Meyer, Dr. Dog, Karl Denson’s Tiny Universe, Trombone Shorty & Orleans Avenue, Blitzen Trapper, Edward Sharpe and the Magnetic Zeros, Lotus, March Fourth Marching Band, The Radiators, Cornmeal, The New Mastersounds, Preservation Hall Jazz Band, Carolina Chocolate Drops, The Mother Hips and Nels Cline Singers, among many others.

Longtime High Sierra favorite The Slip played a rare show and appeared under its Surprise Me Mr. Davis alter ego. The Slip proper’s set marked the trio’s 13th consecutive appearance at the festival and featured material from the group’s more indie-centric Eisenhower album (“Paper Birds”) and earlier material (“Weight of Solomon”). The band also invited out a series of guests, including saxophonist Skerik, saxophonist Joe Conte, Surprise Me Mr. Davis frontman Nathan Moore and Big Light’s Fred Torphy, the latter of whom appeared on “The Shouters.” Vince Herman, a veteran High Sierra performer who has played everything from surprise campground sets to a co-headlining slot with Leftover Salmon, also performed with Great American Taxi. During Great American Taxi’s set, he celebrated the festival’s anniversary by remarking “4:20 for 20 years.”

Railroad Earth turned into two shows, including a late night set in the High Sierra Music Hall Friday night. During the performance, Darol Anger played violin on “The Cuckoo” and Scott Law emerged to add electric guitar to “Birds of America.” Yet, perhaps guitarist Eric McFadden took home the weekend’s sit in award. In addition to his appearance with Panic, the roving guitarist sat in with Wilco’s Nels Cline and Nis Nels Cline Singers, Jerry Joseph & Wally Ingram and the Guitarmageddon jam session.