Glimmer, shimmer, pirouette and ping-these are the things Iceland’s Sigur R€s capture on this Split Sides* performance, a collaboration with the Merce Cunnigham Dance Company performed live at the Brooklyn’s Academy of Music’s 2003 Next Wave Festival. Three pieces by Sigur R€s embody sublimation and evaporation, the sound of a porcelain ballerina caught tick, tap, ticking on a gummy sprocket, then tugging free as melodies billow and retract like warm breath against wintry glass panes. Still, the music is never quite fluid. No closing spurt of distortion or prior amount of poise can conceal that Ba Ba Ti Ki Di Do is more a holding pattern for Sigur R€s-delicate and graceful like the figure mounted to a music box, but far from revelatory.