Five years ago, Sheppard were told by a well-known Australian musician they'd only ever make it as a cruise ship band.
Fast-forward to 2017, and the ARIA-award winners have opened for Keith Urban, Megan Trainor and now Justin Bieber on the Australia/New Zealand leg of his Purpose world tour.
The Brisbane six-piece behind 2014's viral hit Geronimo are clearly making more mileage now than they would have out at sea, and lead singer George Sheppard says they've been very happy to surpass expectations. So have they thought about making a smug phone call?
"The thought was there. When we won the ARIA for best group that's when I really wanted to say something. But I try to stay classy," George says.
Sheppard are siblings George, Amy and Emma Sheppard, rounded out by Michael Butler, Jason Bovino and Dean Gordon. They've made a career out of writing extremely catchy pop - Rolling Stone Australia said their debut album Bombs Away contained "more hooks than a tuna fleet".
They're gearing up to release their upcoming second album, with first single Keep Me Crazy dropping last week. While George, Amy and Jason wrote every track on Bombs Away, the new album involved travelling to LA to meet with other songwriters, which George says was "kind of like speed dating".
A record-breaking single is hard to follow, however, and George says there were moments when the pressure to write another Geronimo became a hindrance.
"You start a song and you're like, oh wait, this is not a Geronimo, so you stop, which is a really bad thing because it's a great song in its own right.
"We started to realise we were having this problem with the pressure we were getting, so we were able to let it go and just start writing again from the heart. It was nice, that moment; it was like, 'ah, okay, relax'."
George says they're "stoked" to be coming to New Zealand - Saturday's Mt Smart Stadium show will be their first performance here. It's the last of their run of shows with Bieber, and George says the experience of playing to stadium-sized crowds has been "surreal".
"You try to take a mental snapshot of it when you're in the moment, but you still feel like you don't take it in until you've gone off stage. You're like, hang on a second, what the hell just happened? That didn't feel real."
Who: Australian band Sheppard
What: Opening for Justin Bieber
When: Saturday, on stage at 6.30pm
Where: Mt Smart Stadium