As concert performances go, Umphrey’s McGee can run hot and cold. Sunday night, they were on fire. Normally reminiscent of a free-form rock group like Phish, Umphrey’s McGee brought their sound down to a heavier tone at the Observatory.

The show started early and finished late. Spafford began playing 15 minutes after doors opened at seven. Umphrey’s McGee struck a final encore chord at around 11:45, savoring the music of the moment and the strong, ever-building energy of the crowd.

Although the band’s first set was solid, they came back after a brief intermission fired up and delivered the stronger fist of their one-two punch. The light show was hypnotizing, and the crowd, an interesting combination of plaid-clad San Diego hipsters and the Dead Head once-was, seemed to fall under its spell.