BY MELISSA RUGGIERI

The pop smorgasbord at Power 96.1's annual "Jingle Ball" concert started with Charlie Puth, ended with Justin Bieber and in between gave a sold-out crowd of very, very excited fans music from Hailee Steinfeld, a pair of Jonai (Joe Jonas and his DNCE group and Nick solo), Fifth Harmony and Shawn Mendes.

Here are some things we learned:

-- Joe Jonas' new electro-pop project DNCE is pretty much what the parents accompanying their teen progeny to the show would call disco. And no, that isn't a bad thing. The three-piece band, including shirtless bassist Cole Whittle (formerly of Semi Precious Weapons), is a tight, funky little crew and Jonas obviously knows how to steer a set. From the glistening "Pay My Rent" to the finger-snapping groove and Jonas falsetto coating "Toothbrush" to the giddy goofiness of hit "Cake By the Ocean," DNCE ably demonstrated their determination to be one heck of a party band.

-- I know I'm supposed to "get" The Chainsmokers. But I'm sorry, I don't.

-- While The Chainsmokers’ button-pushing and mixing behind their lighted altar contributed nothing but a beat to fill the air for 15 minutes, their set was far less egregious than what came after it – a lengthy video ad for a local plastic surgeon. Really?! In a room full of teenage girls already likely dealing with puberty-induced self-esteem issues? Yeah, that’s brilliant.

Fifth Harmony show off their girl power. Photo: Robb D. Cohen/www.RobbsPhotos.com.

Credit: Melissa Ruggieri

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Credit: Melissa Ruggieri

-- Fifth Harmony showed their respect for the holiday that these Jingle shows are ostensibly about and launched their set with an a capella version of "Silent Night." It was lovely – and pretty much the only time the fivesome sang completely live. They gyrated with Best of Beyonce moves to "Boss" and exhibited their girl power credo with "Reflection" and "Sledgehammer." Their music is achingly generic, but their target demographic adores them. The girls closed their performance with their multi-platinum single, "Worth It," complete with that (recorded) horn line that sounds litigiously close to Jason Derulo's "Talk Dirty to Me."

-- Shawn Mendes is only 17, but he clearly has designs on being the American Ed Sheeran. His acoustic set showcased his pleasant, if non-descript voice on "Something Big" and his current hit, "Stitches," while his duet with Fifth Harmony's Camila Cabello on "I Know What You Did Last Summer" soared. He's one of the latest teen boy heartthrobs, but Mendes does, refreshingly, seem focused on song craft without the usual trappings.

-- Oh, Nick Jonas, so cool in shades and a stylish black jacket, soon discarded so the swooning girls in the crowd could get a better glimpse of his manly biceps. The emergence of Jonas as a credible singer has been a pleasant surprise, and he sounded strong and soulful on his hit "Stitches" and the groove-thumper "Let's Take it Back," which featured a tease of Tupac Shakur's "California Love." Besides, how can you not love a guy who, after turning up the funk with his snappy four-piece band on "Levels," segued into Bell Biv DeVoe's "Poison" and then went acoustic for "Who I Am?

Both Nick and Joe have female guitarists in their bands. Photo: Robb D. Cohen/www.RobbsPhotos.com.

Credit: Melissa Ruggieri

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Credit: Melissa Ruggieri

-- Jonas was barely offstage before chants of "Jus-tin! Jus-tin!" filled the arena, proving, in case anyone was wondering, that teen girls are a forgiving bunch. The man of the night made an unassuming entrance, clad in black and a camouflage trucker hat, and immediately went into dance mode with his backup crew on "Where Are U Now." He stalked the stage, reminding the crowd that he used to live in Atlanta – "It always feels like home when I come back," he said – then called on guitarist buddy Dan Kanter to assist him on an acoustic set…which eventually started after Bieber left the stage to retrieve water (he flipped a bottle to a fan in the front row and the reaction was as if he had turned the water into wine), tinkered with his mic stand and fiddled with his gold tooth.

Bieber joked that he needed some time in the gym. Photo: Robb D. Cohen/www.RobbsPhotos.com.

Credit: Melissa Ruggieri

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Credit: Melissa Ruggieri

He's still boyish and baby-faced and excels at milking moments – but when he focuses, it is impossible to argue the guy's talent as a singer. "Love Yourself," "Hold Tight" and "Mistletoe" featured Bieber's sweet vocals and even though the mechanical thumps backing "As Long As You Love Me" and "What Do You Mean?" overshadowed any chance of a spotlight vocal, they showcased Bieber's ability to effortlessly slip into a groove. Perhaps the most humanizing – and amusing – moment of his set came when the crowd began to chant for Bieber to take off his shirt. He shook his head and grinned, "I gotta get a few more months at the gym before I take my shirt off." So, girls, you know what you have to look forward to when Bieber returns to Atlanta in April.

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