All those bubble-gum hits you couldn’t scrape from the roof of your skull this year? On Tuesday night, they were all stuck under the roof of the Patriot Center.

Local radio station Hot 99.5 was hosting its first Jingle Ball, a three-hour, Christmas-tinted pop marathon that included Justin Bieber, Ke$ha, Flo Rida, “Gangnam Style” rapper Psy and more.

These events aren’t new to Clear Channel, the radio behemoth that owns Hot 99.5 and that has hosted ballyhooed Jingle Balls in New York and Los Angeles. The performances are short and ear-splitting. The crowds are young and ear-splittinger.

Tweenage wailing aside, there’s an accidental genius to a concert like this. The acts either vanish before you have time to get sick of them, or they split leaving you wanting more.

Tolerable in mini-doses: a quick set from Flo Rida, whose charmless rapping suddenly felt cute when thousands of spastic kiddos pumped their tiny fists to it.

Way too short: A five-minute appearance from a tuxedoed Psy, who threw lung and limb into “Gangnam Style” and then galloped off into the sunset.

Clocking in at 35 minutes, Bieber’s set fell somewhere in between. He had more pep in his sneakers than he did at his listless Verizon Center gig in November, and he made time for a couple of leisurely, unplugged ballads before finally clocking out with booming, boastful versions of “As Long as You Love Me,” “Boyfriend” and “Baby.”

Ke$ha’s time on stage was the loudest in every sense. Dressed like a sci-fi superhero, talking trash like the pal you first befriended in detention, she delivered nasal raps over kidney-quaking bass melodies.

Cher Lloyd, a 19-year-old who matriculated from Simon Cowell’s original U.K. version of “The X Factor,” flaunted just as much attitude as Ke$ha, at half the volume. Petite and tattooed, she provided the evening’s first smile with “Want U Back,” a frustrated love song riddled with angsty grunts. The audience didn’t miss the cue to join in: Everybody UNNGH!!

The rest of the night was spent screeching — even for Enrique Iglesias, who, compared with the other acts, seemed downright AARP-friendly at 37. When he launched his pillowy 2001 ballad “Hero,” the youngest fans in the building were crooning along to a song recorded when they were still eye-glimmers.

For plenty of them, this was My First Concert, but it still had the familiarity of a night on the living room couch. Between performances, commercials flashed on the JumboTron, advertising hamburgers, breakfast cereals and winter coats.

The only thing weirder was pleasantly weirder: a gentle, understated, three-song set from Ed Sheeran, a 21-year-old Brit with a nest of red hair who has lent his songwriting smarts to Taylor Swift and One Direction.

Toting a miniature acoustic guitar, he sang with a folky sweetness and an R&B-ish agility. You could hear both qualities most clearly with “The A Team,” a song about a homeless drug addict trying not to crumble.

Few lumps of coal taste so bubble-gum sweet.