Question:  Sigur Rós' EP consists of the songs the group composed for an American dancer and choreographer who was at the forefront of the American modern dance for more than how many years?
Sentence (from "Sigur Rós discography"): The discography of Sigur Rós, an Icelandic post-rock group, consists of seven studio albums, one remix album, three extended plays, one soundtrack album, fourteen singles, nine music videos and two video albums.
Relevant evidence: No