It's a measure of how far Bangor's most-accomplished indie poppers have come in even the past year that they were headlining Belsonic — and even sold the place out.
Also, like the fledgling stars they are, Two Door Cinema Club took what seemed an age to set up after Noah and the Whale, with roadies beavering away to a soundtrack of relentless cheesy house.
If you sped it up it'd be like that Benny Hill sketch, although thankfully the saucy tech crews’ clothes stayed on.
And then the opening chiming bars of Cigarettes in the Theatre echoed across Custom House Square.
“Hello Belfast — thanks for being here,” said a youthful, brash and beside-himself Alex Trimble.
“It's been a while. There’s definitely a lot more of you than last time,” he added with only a little self-satisfaction.
It's well earned though.
Their exuberant Northern Irish teen anthem This Is The Life was all rippling hi-life guitar and beguiling brio.
It wasn't the first time the partisan crowd went ‘nuclear’ last night.
Even the hard nosed, Toby-jug chap bellowing by the Absolut Bar knew every word.
New track Wake Up showed that forthcoming album Beacon will continue where Tourist History left off — with a Kaiser-Franz-Chief-Ferdinand belter.
New single Sleep Alone — a chiming, pulsing Two Door instant classic — had more hooks than an Abu Hamza fancy dress party.
“We played this song for the first ever time round the corner in the Spring and Airbrake. It was a free show,” reminisced Kevin Baird before the band dispensed another choppy, irresistible white disco gem, Something Good Can Work.
All the while the crowd roared, danced, sang, waved, laughed — and even cried a little.
But for the most part, pop music fans gave thanks that Two Door Cinema Club mitched off bandcamp to craft a batch of gloriously uncynical and instantly memorable tunes on the day the rest of their peers were trying to re-invent the wheel.