Last Wednesday night was a big night for Sigur Rós fans in Boston. The Icelandic ambient, post-rock band took the stage of the Boch-Wang Center in an unconventional way. Instead of having any openers and set changes, the band performed two acts with an intermission in-between. Frontman Jonsi sang with eerie emotion while lights flashed and videos featuring imagery of birds, children, and abstractions played in the background. The whole venue erupted with applause when the band finished the set, slamming on their instruments, as Jonsi screamed into the front row of the audience.