Pentatonix, (from left) Kirstin Maldonado, Kevin Olusola, Scott Hoying, and Avi Kaplan, performs at the American Airlines Center on Sunday, Nov. 20, 2016, in Dallas.(Smiley N. Pool/The Dallas Morning News)

Pentatonix, (from left) Kirstin Maldonado, Kevin Olusola, Scott Hoying, and Avi Kaplan, performs at the American Airlines Center on Sunday, Nov. 20, 2016, in Dallas.(Smiley N. Pool/The Dallas Morning News)

Staff Photographer

The Arlington-bred vocal group Pentatonix has played homecoming shows before, but none quite as impassioned as its concert Sunday night at American Airlines Center.

Audience members cheer as Pentatonix performs at the American Airlines Center on Sunday, Nov. 20, 2016, in Dallas. 

Audience members cheer as Pentatonix performs at the American Airlines Center on Sunday, Nov. 20, 2016, in Dallas. 

Smiley N. Pool/Staff Photographer

"This is the biggest headlining show we've ever played and all our family, friends and old teachers are here ... This is a crazy visual," said Scott Hoying, the quintet's lanky blond baritone, as he looked out at 18,000 cheering fans.

"I won't talk much because I'll get too emotional and I'll start to cry," said mezzo-soprano Kirstin Maldonado. She managed to hold back the tears, but she got so unglued that she botched the spoken intro to the next song, Dolly Parton's "Jolene."

Yet when they sang, not a single errant note was heard. 

In an era of vocal auto-tuning and lip-syncing, Pentatonix are that rare group of singers who can glide up and down the pentatonic scale in perfect pitch, timbre and harmony.

Three of the members of Pentatonix are from Arlington: the middle three, Kirstin Maldonado, Scott Hoying and Mitch Grassi. Avi Kaplan (on left) and Kevin Olusola (on right) round out the group.

Three of the members of Pentatonix are from Arlington: the middle three, Kirstin Maldonado, Scott Hoying and Mitch Grassi. Avi Kaplan (on left) and Kevin Olusola (on right) round out the group.

Smiley N. Pool/Staff Photographer
Pentatonix won a cappella TV contest 'The Sing-Off' five years ago. Look at them now.

Pentatonix won a cappella TV contest 'The Sing-Off' five years ago. Look at them now.

Smiley N. Pool/Staff Photographer

They've hit amazing heights in the five years since they formed to compete on NBC's The Sing-Off. Last fall, they became the first a cappella group to score a No. 1 album on the Billboard 200 with Pentatonix, their fourth full-length release but just their first collection of mostly original tunes.

The group sang the bulk of that album Sunday night, and inevitably, some of their own songs dragged compared to their stock-and-trade cover tunes, which included hits by Meghan Trainor ("No"), Omi ("Cheerleader") and "Daft Punk," their Grammy-winning medley of songs by the French electronic-pop duo. Even harder to top was "Evolution of Michael Jackson," a tongue-twisting hodgepodge of "ABC," "Man In the Mirror" and a dozen Jackson hits in between.

Performing on a sparsely-set stage featuring five rectangular video boxes, Pentatonix didn't try to put on a bombastic arena show. They kept dance moves to a minimum, saving their oxygen for their singing. The audience stayed fairly sedate, too -- most of the crowd remained seated, a rarity at big pop shows.

Tribute to Leonard Cohen: Watch Texas singers Pentatonix expertly cover 'Hallelujah'

But what the show lacked in visual pizzazz it made up for in vocal fireworks -- especially in the soaring high notes of Mitch Grassi and the tight rhythmic interplay of bass singer Avi Kaplan and singer-beatboxer Kevin Olusola, the only two members not from Arlington. Olusola briefly broke the a cappella spell when he played a cello and added vocal beats for a bizarre "cello-boxing" rendition of Bach's Prelude and Fuge in C Major.

If you're not a big fan of a cappella singing, the show felt at times like an elaborate parlor trick with too little space between the notes. But just when it seemed the pace would never slow, the band launched into a gorgeous set-closing version of "Hallelujah," Leonard Cohen's sublime but thorny meditation on love, sex and religion.

On record, Pentatonix's version sounds strangely peppy. But in concert, with thousands of cell phone flashlights illuminating the arena, their voices took on a supernatural glow.

Thor Christensen is a Dallas writer and critic. Email him at thorchris2@yahoo.com.

Look through gorgeous photos of Pentatonix's hometown concert at American Airlines Center in Dallas:

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