Beneath the bright blue cathedral walls and exposed beams of muted red hue, a congregation of a different sort has come for their dose of worship on this sweltering July evening. During this sermon no words will be spoken, but the message promoted from the pulpit by the rugged post-rock instrumental band Tortoise would indeed cast a spell on the mostly sinful throngs of hipster parishioners.

Touring behind their latest album Beacons of Ancestorship, the Chicago sextet breezed and battled through smooth and frenetic passages from the get-go, smattering fractions from their entire catalog throughout the sold-out sanctuary. The only way to describe fantastic instrumental music and to put you where I was, witnessing what I did, is to close these eyes, piece together footage from “songs” that often bled together and rhythmically entwined themselves in impossible knots, and give you some freeform play-by-play.

Picture this: an offtempo battle between face-to-face percussive front lines formed a sound bed for spaced cadets who shunned a sedentary starbase stance for an epic wind rush of propulsion, bottom, and eventual blastoff and landing on a nameless planet with valuable pockets of untouched energy. Picture that: A dark jazzy western where twin lead guitars whistling in from the high plains on a ghostly gallop suddenly veer off into the faux noir panic of a French thriller, shadows of bass following a faceless figure skirting through a rainy alley with warmth and surprise, then ambush. The maker is met.

I cannot think of one epic moment from this night which failed to fit the multitude of soundtracks created and deconstructed by the dancing faithful. I reveled in the idea that any number from the Tortoise body of work could be the framework, the very outline of a film rather than the background music for it. This is no background music. Tortoise have a tight grip on the realization of sound ad infinitum.