Hansard and Irglová performed the song live on the Oscar broadcast at Los Angeles' Kodak Theater on 24 February 2008.
When they went on stage to receive their awards, her acceptance speech was preempted by the orchestra's music cue to leave the stage.
The following year, the duo received an Academy Award for Best Original Song for the film's hit single, "Falling Slowly," and the Swell Season's popularity surged as a result.
Once: Music from the Motion Picture went gold in February 2008, and an accompanying tour saw the group performing to sold-out crowds in multiple countries.
In 2007, she co-starred with Hansard in the indie movie Once, written and directed by John Carney.