Julianna Barwick strips music to a few basic ingredients: the human voice, and often just two or three pieces of technological equipment.

Primarily using just a looper, a sampler and keyboard, she sings brief, occasionally wordless, phrases into a microphone, loops them, and builds them atop one another until a full choir blossoms from the small components. She typically accompanies these vocals with minimalist, repetitive keyboard passages that slowly cycle through keys, not unlike a Philip Glass composition.

The total effect is stunning – her 2011 album “The Magic Place” and her 2016 album “Will” are among the finest records of recent years. They’re stately, celestial and otherworldly, sounding like the Cocteau Twins sprinkled with American gospel and a dash of Enya.

But what happens to her live performance when she is unable to loop her voice?

That was the issue at SPACE Gallery in Portland this past Friday. At the start of the show, a broken-up Barwick explained to the crowd that her looper fell off of her setup and broke, and that she’d be returning to Maine this summer to play a proper show.

As this piece of equipment is essential to what she does – imagine Jimi Hendrix breaking his guitar just before going onstage – nobody would have blamed her for canceling the gig. Instead, she played the songs she could play without the benefit of layering her voice to create her usual sonic bedrock.

To her ears, the whole performance likely sounded off. To fans who are deeply familiar with her catalog, swaths of the show were barely recognizable from their studio recordings. But to most audience members, and particularly those who were unfamiliar with her work, it no doubt sounded like heaven. While Barwick has astute compositional sensibilities and is an expert at using technological tools to realize her ideas, her greatest asset will always be her voice – which requires little gadgetry to move listeners.

She displayed a lower register that you could luxuriate in, reverberating mightily off the walls of the venue, and also a higher range that was both full-bodied and ethereal at once. The room was dark, the tempo was slow, and the music was loud. As is typical with her performances, it was less a concert than a spiritual, meditative experience.

It’s difficult to imagine what kinds of challenges the performance presented for Barwick, who played at the Middle East nightclub in Cambridge, Massachusetts, the evening before and had less than 24 hours to drive north, try to fix her looper and throw together an unrehearsed set. Regardless of how it was accomplished, she succeeded, and if she really does come back this summer, it’s not a show to miss.

Cellist and songwriter Nat Baldwin opened for Barwick. Baldwin’s work is influenced by 1980s avant-garde cellist Arthur Russell (he even performed a terrific cover of “A Little Lost,” one of Russell’s finest works), but also stands apart from that influence, as on his affecting “Wasted.”

Baldwin is associated with a number of highly regarded indie-rock bands; he is a member of Dirty Projectors, and has appeared on albums by Vampire Weekend and Grizzly Bear. He’s also a native of Portsmouth, New Hampshire, and has been a regular at Maine venues for many years. This was his first performance as a resident of Portland, however, and we’re excited to have him here.

Robert Ker is a freelance music writer in Portland.