Kirstie Maldonado commands the stage with fellow Pentatonix members Kevin Olusola, Scott Hoying, & Avi Kaplan (Sarah Mickelson/Neon Tommy)

From the outside, the Fonda doesn’t amount to much, but once inside, it’s hard not to gawk at the ornate twenties interior that extends from the foyer to the intimate main room.

Pentatonix, a five-member a cappella group that catapulted to fame after winning Season 3 of NBC’s "The Sing Off," drew a crowd that filled the ballroom almost entirely.

The audience was surprisingly eclectic, ranging from pre-teens to college students to retired seniors. One man brought his wife to the show in celebration of his 65th birthday.

With an appeal to a wide range of ages, it’s no surprise that the audience remained refreshingly tame throughout the duration of the performance: mosh pits and sloppy drunks were nowhere to be found.

Pentatonix opened with a bang: they covered a pop tune while surrounded by a flurry of backup dancers. But the choreography remained minimal so as not to take away from their beautiful voices.

They were sure to sing Beyoncé and Lady Gaga’s hit “Telephone,” particularly meaningful because it was their audition song for "The Sing Off." Other notable songs they covered were Imogen Heap’s “A Ha” and Macklemore and Ryan Lewis’ new hit “Thrift Shop.”

At one point they brought a lucky girl up to the stage and serenaded her to Marvin Gaye’s “Let’s Get It On.” The girl was clearly star struck but made sure to snap selfies of herself on stage with USC’s own Scott Hoying.

She wasn’t the only one in awe of the group though—one girl had tears streaming down her face during a moving rendition of Florence + The Machine’s “Dog Days Are Over.” Dare I say some songs sounded even better than the originals!

One lucky girl gets serenaded while Pentatonix sings "Let's Get It On" (Sarah Mickelson/Neon Tommy)

The group’s only girl, Kirstie Maldonado, blew us away with the lead on their cover of Calvin Harris and Florence Welch’s “Sweet Nothing.” YouTube sensation Kevin Olusola treated the audience to a mesmerizing display of talent when he beatboxed at the same time as playing the cello. And while the other members took a short break, Kevin and Avi Kaplan gave the audience a taste of their awe worthy vocal abilities, entertaining us with sounds we didn’t know humans could make. Not to be outdone, Mitch Grassi’s amazing range was the cherry on top of a great show.

It was hard not to notice their grateful smiles every time the crowd screamed their praises. Clearly Pentatonix is genuinely thankful for their fans and success. The fact that they didn’t make the audience wait long for an encore furthered that notion and reminded us that successful, talented people don’t always have to be divas.

Pentatonix is leading the movement to make a cappella mainstream and have quickly accumulated a large following of adoring fans, otherwise known as Pentaholics.

While known for their covers, Pentatonix also gave the audience a sneak peak of some of their original songs. This group is moving up the charts, and I wouldn't be surprised if they became Grammy nominees a few years down the road.

Pentatonix’s first EP is in stores now and they’re going to drop their second sometime this year; this Pentaholic looks forward to hearing new covers and more original songs.

Read more of NT's show reviews here.

Reach Staff Reporter Sarah Mickelson here.