T he truth underlying the name Grouplove would be annoying if the band wasn't so casually sincere about it.

It's clear that they all love each other -- the band members were friends and the music was a by-product of friendship. Guitarist Andrew Wessen and drummer and producer Ryan Rabin grew up together in Los Angeles. Wessen's brother invited keyboardist Hannah Hooper to an artist residency in Greece, and Hooper invited singer Christian Zucconi to come along only a week after meeting him in New York City. Bassist Sean Gadd, a Londoner, happened to be at the commune, too.

At the time, Hooper had no music experience. She was a painter, but she found her musical side in Greece and it's very strong booze.

"When you're in Greece, there's this really strong alcohol, and everyone was sitting around drinking, and everyone was singing. I don't know, it might have been the alcohol. I was just really comfortable and just started singing along with everyone," Hooper said. "There's like this weird kind of seamless way that I started making music the way I was painting before. I guess I feel like I'm lucky. It was natural."

The group dynamic was natural, too. Back in the States, the group gathered in L.A. and the music just started to happen.

"About a year after Greece, we all, you know, we kept in touch. I was worried our relationship was gonna fade summer camp-style," Hooper said. "We ended up saving up and going out to L.A. and staying with Ryan. We started just as friends playing musc and Ryan was like, 'Let me record some of these songs we're playing together' and that was the EP."

They didn't consider themselves a band, but the EP reached the ears of Grouplove's future manager, who started promoting the music and encouraged them to keep going.

Grouplove's full-length debut, Never Trust A Happy Song, was huge hit. The band ended up selling out its first show, albeit in a dumpy (according to Hooper) Mexican restaurant in L.A. The insistently joyful single "Tongue Tied" -- you know, "Take me to your best friend's house / I loved you then, I love you now" -- reached that weird level of indie smash hit when it was feature in an iPod commercial.

"It was crazy how quickly I felt like it caught on," Hooper said. "There was a buzz going on that none of us were expecting or trying to have. There was just this energy and we were excited."

The album's title is just a plainly meaningful as the band name, in a sweet, touching way.

"Sean said "never trust a happy song" when we were in Greece. We were writing a bunch of happy music and none of us considered ourselves paritcularly happy people, but we were laughing and having a good time. We kick out the negative when we're together," Hooper said. "A song that may seem happy that isn't always a happy song. Or a sad-sounding song can be about something happy. A lot of people consider us to be the happiest band of all time, but a lot of the songs start off much darker places."

Grouplove does sound wildly, insanely happy. Its bouncing, shimmying indie pop is sprinkled with sha-la-la-la's and ecstatic howls. And since selling out the first gig, Grouplove have gone on to sell out Denver's Ogden Theatre and the Fillmore in Hooper's native San Francisco. Whether or not they're all naturally happy people, it sounds like they're feeling pretty good now.

Hooper laughed and said, "I don't wanna wake up from this."

Hear Grouplove live at the sustainable Cultivate Food, Ideas & Music Festival at City Park, 2400 York St., Denver on Saturday. The festival is free and also features Best Coast, Okkervil River, Tennis and Zach Heckendorf.

If you go

What: Grouplove

When: Saturday at 3:45 p.m.

Where: Cultivate Food, Ideas & Music Festival at City Park, 2400 York St., Denver

Cost: Free

More info: chipotle.com/cultivate