Summer Camp Music Festival will reveal its initial lineup tomorrow, December 21, but today the fest added a special guest to the annual summer event in Phil Lesh, who will be joined by The Terrapin Family Band for his Summer Camp set.

The announcement was made via a video of Lesh interrogating moe. members Al Schnier and Vinnie Amico about their destination as they pack up their van. moe. are co-hosts of Summer Camp along with Umphrey’s McGee. The video also shows Lesh’s son and Terrapin Family Band guitarist Grahame and Everyone Orchestra bandleader Matt Butler joining in on the road trip. Watch below.

The first round of Summer Camp 2018 artist announcements drops tomorrow. The festival is set to return to Chillicothe, IL, on May 25–27. All festival information can be found here.