San Rafael, CA’s Terrapin Crossroads has announced the lineup for their Summer Jam, which will take place on September 17 and will feature Phil Lesh & Friends, Brothers & Sister and Terrapin Family Band, along with special guests and surprises.

Lesh will be joined by Friends Stu Allen, Grahame Lesh, Scott Guberman, Ezra Lipp, Alex Koford and Scott Law, with special guests promised to appear.

Terrapin Crossroads has also announced that the first 400 fans who purchase tickets to Summer Jam will get free tickets to a show in the Grate Room the previous night, September 16, that will feature Lesh & Friends playing the Grateful Dead’s legendary “Watkins Glen Soundcheck” from the band’s rehearsal at the famed Summer Jam in Watkins Glen, NY, in 1973. The 400 winners will be notified by email.

More information on Terrapin Crossroads’ Summer Jam is available here.