 There were limitations, however, because of the build-up of noise during the bouncing-down process, and the Abbey Road engineers are still justly famed for the ability to create dense multitrack recordings while keeping background noise to a minimum.4-track tape also led to a related development, quadraphonic sound, in which each of the four tracks was used to simulate a complete 360-degree surround sound.A number of albums including Pink Floyd's "The Dark Side of the Moon" and Mike Oldfield's "Tubular Bells" were released both in stereo and quadrophonic format in the 1970s, but 'quad' failed to gain wide commercial acceptance.