The Nancarrow Barrow was made in 2008 as a response to the Critical Mass Cycle Rides that can become quite confrontational, offering a celebration of cycling to Londoners. It is named after the American composer Conlon Nancarrow (who wrote many studies for mechanical player pianos). It is made from reclaimed materials. The music is created by the wooden objects inside the Barrow falling on the chime bars as the wheels roll and the beaters hanging from the arch above the back wheels strike the chime bars as they pass. The music changes as the speed changes.