Swell Season Cover Van Morrison, Bonnie 'Prince' Billy at Nelsonville Music Festival

At the final day of the Nelsonville Music Festival, Sunday headliners the Swell Season entertained the peaceful crowd with a wide variety of songs from the 'Once' soundtrack and their two albums. Additionally, the Irish folk rock duo infused their early-evening set with traditional Irish folk songs and several covers, including a version of Van Morrison's 'Astral Weeks.'

The Swell Season and its backing band opened with what singer and guitarist Glen Hansard described as a "semi-local song":Bonnie "Prince" Billy's 'Ohio River Boat Song.' While much of the crowd seemed unfamiliar with the song, it was refreshing to know that Hansard was actually quite aware of his location. The local love continued when Marketa Irglova, the duo's singer and pianist, complimented the three-day festival, which takes place in the Appalachian hills of Southeast Ohio. "This is a lovely festival, my kind of festival. We went for a long walk around here today and are enjoying the nature," Irgolva told the crowd, adding that the festival reminded her of one back in her home country, the Czech Republic.

Throughout the show, the duo displayed a very personal streak to the crowd. Hansard took his time introducing songs, saying charming things like, "This song is about keeping your eye on the ball and keeping the trajectory of your heart as straight as an arrow -- whatever the hell that means," when introducing 'In These Arms.' While Irglova's demeanor was sweetly shy, Hansard was chatty and slightly goofy. He even inserted several bars of 'Sexual Healing' into their soulful song, 'Low Rising.'

It seemed as though the audience couldn't be more endeared by the duo until Hansard did something adorable and unexpected -- he literally plucked a young girl from the crowd and lowered the mic so she could sing several bars of the Swell Season's Oscar-winning song, 'Falling Slowly.' "This girl's going to sing a bit of our next song," Hansard said, grinning. The girl, who apparently sang for him earlier in the day, obliged before being returned to her parents.

The show continued on with more participation from the respectful crowd as Hansard taught fans the words to a traditional Irish funeral song during the band's encore. When introducing the final song, Hansard stressed the "importance of the aural tradition. Learn songs from your grandparents -- that's where the gold is."