The three pieces of music comprising "Ba Ba Ti Ki Di Do" were originally written for the Split Sides performance of the Merce Cunningham Dance Company. The members of Sigur Rós performed them live at the Brooklyn Academy of Music's 2003 Next Wave Festival, New York on October 14, 2003, and again in Paris at The Theatre de la Ville in December 2003. On these occasions, the band improvised a 20-minute section of music over a previously recorded backing track using two sheet-fed music boxes, a glockenspiel, and a homemade percussive instrument ("bummsett" in Icelandic) made of eight ballet shoes on a rack. The backing tracks incorporated recordings of Merce Cunningham's voice and the sound of his tap-dancing feet. The results of this live improvisation (which came to mirror some elements of the choreography) were recorded at the band's studio outside Reykjavik, Iceland in late November 2003. The three sections -- "Ba Ba," "Ti Ki" and "Di Do" -- are designed to be played in any order.