The principal members of MGMT sat in with the psych-rock band Spectrum at Brooklyn, NY’s Knitting Factory last night. MGMT keyboardist Ben Goldwasser and frontman Andrew VanWyngarden joined the group onstage at the start of its encore for the Silver Apples’ “A Pox on You.” The musicians later returned for a jam leading out of Spacemen 3’s “Suicide” that featured Goldwasser on synthesizer and VanWyngarden on auxiliary percussion. The musicians then both switched to effects pedals and other digital toys for the improvisational number that closed the night. The jam segments spiraled on for almost 20-minutes.

Spectrum’s Sonic Boom, who made his name in Spacemen 3, produced MGMT’s new album Congratulations. The musicians are featured on the June cover of Relix.