'' WTC 9/11 '' consists of three movements , listed below , although there is no pause between movements , and the tempo is consistent throughout the entire piece . The three movements last approximately fifteen and a half minutes in total . Reich stated that he tried to make it longer , but that " the piece wanted to be terse . " The first movement , 9/11/01 , begins and ends with a violin imitating the sound a phone makes when left off the hook . Voice recordings in this section begin with NORAD air traffic controllers concerned with the off-track American Airlines Flight 11 , and move to FDNY recordings related to activities on the ground . Voice recordings in the second movement consist of parts of interviews conducted in 2010 by Reich . In addition to voice recordings , two string quartets are pre-recorded for the performance . Alternatively , the piece can be performed by three string quartets with pre-recorded voices only
American Airlines Flight 11
American Airlines Flight 11
WTC 9/11