Last night, British indie sensation The xx held a concert downtown at the Wilbur Theatre for a completely sold-out crowd—although “concert” may be an ill-fitting descriptor for the experience.

What guitarist/singer Romy Madley Croft, bassist/singer Oliver Sim and beatmaster Jamie Smith produced in the theatre seemed more akin to a religious experience:  not a soul in the pit was dancing for the majority of the set. Rather, each person stood, often with eyes closed, softly singing along. A glace back at the balcony showed rows upon rows of grave faces gazing with enraptured intensity at the band’s hushed, suave vocals and minimalistic instrumentals.

The only album released thus far by The xx came out in 2009 to critical acclaim and was widely acknowledged to be a “nighttime” kind of album. Praised for its minimalism and whispery nature, the album was largely recorded by the former schoolmates in the middle of the night. According to Sim, this accounts for some of the whispery sound of the songs:  they played as quietly as possible to as not to wake the rest of the house during recording sessions.

Indeed, they still sounded hushed at the Wilbur, so much so that I felt an uncharacteristic urge to shush anyone singing along around me so I could hear Sim and Croft’s uncannily gorgeous harmonies stand on their own. I found myself irritated when the crowd would shout during softly reverent numbers like “VCR” and newly released single “Angels”, as though they had snapped me out of a Zen-like trance, so powerful was the spell cast by the music.

While it might seem boring to those reading about it after the fact, The xx did pick up the pace about halfway through, catering to electronica lovers with yet-unreleased tracks off of their second record (due out September 11) which featured bigger hooks and EDM-esque beats. Yet still, somehow, even when the bass shook the floor and made my teeth rattle, the atmosphere felt quiet, restrained even.

Aiding in this meditative-like experience was a mesmerizing lightshow which featured a giant plexiglass “X” hovering above the stage through which an eerie blue light pattern shone through, at one point even resembling a look inside a person’s lungs as they drew in breath, an image unsettling yet simultaneously elegant enough to perfectly complement the performances.

The xx puts on a show that’s not for your typical EDM fan, your typical rock fan, or even your sad-girl song fan. The xx puts on a show that is entirely its own, heartbreakingly beautiful from beginning to end yet enthralling enough to hold a crowd of thousands not only interested, but downright moved.