But when performing, for every song like "Back in Your Head," there's a balance of silliness. Between nearly every song played by the singing-songwriting pair, the two casually — often hysterically — banter back and forth in what amounts to indie music's answer to Laurel and Hardy.
"Sometimes I like it more than music," said Tegan Quin in an interview backstage at the Coachella Valley Music and Arts Festival.
The 27-year-old Quin sisters and their band played at Coachella on Friday, their second trip to the annual desert festival. (In 2005, the excitement of playing the festival was greatly diminished because a case of the whooping cough had weakened two band members.) This time around, Tegan and Sara played a brisk set on the main stage, and while they didn't take too much time to chat, they still found reason to discuss dreams in which David Bowie appears. They also briefly lamented the poor acts that on Saturday were to play at the same time as Prince (the festival's biggest draw).
For Tegan and Sara, who hail from Calgary and released their fifth album ("The Con") last year, such comic relief is nothing new.
"We got on stage that first time to do a show in front of strangers and we finished a song or Sara screwed up or something, and I made a comment," recalled Tegan. "The audience laughed and I was like, `There you go, buddy! This is our thing.'" She believes the roots of their routine likely comes from reacting to all the attention they received as young twins. But it's become an integral extension of their open-book ethos.
"It calms the audience down," said Tegan. "I think it makes them feel like we're real people, not like a rock show or watching television. We're really, actually there."
Said Sara: "You're up there singing your heart out and sometimes you want people to know you're not always like that."
The sisters think they might one day make a mix tape of their best stories and jokes told in concert (they record all their shows). But for now, the comedy of their chatter and the tragedy of their songs will remain separate.
The twins are often asked if they plan any of their banter, but they never rehearse anything but the songs.
"We can barely get together to write a set list," said Sara. "We certainly can't sit and write jokes together."