By Alex Opsahl, Managing Editor, Arts & Entertainment-Lifestyle

Shawn Mendes looked as joyous as his 13,000 screaming fans when he ascended to the Infinite Energy Center stage, acoustic guitar in hand. Mendes’ July 29th performance marked the Atlanta stop on “Illuminate,” Mendes’ third headlining tour since he turned 15 three years ago. Charlie Puth opened the show.

Mendes began the night with the upbeat “There’s Nothing Holding Me Back,” a song whose fast-paced guitar accompaniment has kept it at the top of the Billboard charts for nearly four months. Catchy hits such as “Mercy,” “Stitches,” and “Treat You Better” followed, along with slower piano ballads like “Roses.”

Mendes’ performance was defined by his apparent enthusiasm. He repeatedly reminded the crowd that he was “so grateful” for their support. He seemed unable to keep from smiling, even as he performed more reflective songs like “Ruin.”

Mendes’ fans seemed equally excited. As he rose to the stage, a collective squeal rang from the audience. Throughout the show, fans waved iPhone flashlights and homemade signs reading “We Love You Shawn!” dotted the arena. When Mendes told the audience to “sing it!” during “Stitches,” they knew every word. Outside the arena, even the food vendors were humming along.

The show’s stage decor was simple and kept the audience focused on the performers. During Puth’s performance, the arena was completely lit and the only decorative elements were three screens magnifying the singers’ face. When Mendes took the stage, followed by colorful spotlights, an illuminated sphere dropped down from the ceiling like a chandelier.

Much of Mendes’ brand aligns with boy band trends set by heartthrobs like Justin Bieber and One Direction. His songs describe cookie-cutter scenes of romance illustrated in music videos with many millions of views featuring lithe blonde love interests. He regularly flips his well-coiffed hair, and his concert was populated primarily by teenage girls.

However, Mendes’ music has a folk-acoustic sound which gives a unique twist to his boy band lyrics and aesthetic. His songs forgo synthesizers in favor of organic instrumental accompaniment.

A cover of Ed Sheeran’s “Castle on a Hill” was part of his Atlanta Lineup, and one of his earliest hits was a mash-up of Simon & Garfunkel’s “Cecilia.” Mendes is also unique among heartthrob musicians in that he got his start writing his own songs, which gained popularity as six-second Vine clips.

Charlie Puth opened for Mendes, performing top 40 radio staples like “Attention”, which recently reached the seventh spot on the Billboard “Hot 100 charts”, surpassing “There’s Nothing Holding Me Back.” Puth’s performance was energetic; he spent much of his performance jumping up and down as he sang.

Though he did not elicit the amount of screaming that Mendes did, the popularity of Puth’s songs indicate he will likely headline his own tour soon.