Ever dug a hole at the edge of the ocean? Scoop out some sand, and seconds later, waves fill it in again. That's what the jammed aisles at Merriweather Post Pavilion were like Friday night: Clear away the Phish phans; seconds later, they wash back in. Phish shows are as much about the people as the music anyway, and there hasn't been such a distinctive, pungent assemblage since, well, last year's Phish concert.

The Vermont band was loose and pretty good, nodding and noodling its way through two long sets and encores. Not supreme melodicists, the quartet relies on extended improvisational turns, aiming to avoid Dead-ends. Guitarist Trey Anastasio is good at it, and his fuzzy runs during "The Divided Sky," Latin hops in "Punch You in the Eye" and rockabilly bursts around drummer Jon Fishman in "Get Back on the Train" led the way.

After 16 years, the quartet can conjure any mood it wishes, and set-list choices often strike the faithful as cosmic epiphanies ("Dude! This song is following me!"). On Friday the choices cut a broad swath across the group's catalogue: "Driver," "Mike's Song," which detoured into Aerosmith's "Sweet Emotion," and "Meatstick," featuring "The Meatstick Dance," a rather sickening routine (fans call it "the hippie Macarena") during which keyboardist Page McConnell's wife joined bassist Mike Gordon and Anastasio onstage.

That was unfortunate. Like the hippie fortune cookie says: "Esoteric tendencies of Phish can ruin a whole meal." Friday, that dance very nearly did.