A multitrack recorder is capable of storing multiple independent audio feeds, allowing each element of a song to be recorded on its own distinct track. In a single-track recording, the entire band must play the song correctly from start to finish, and one mistake can destroy the entire take. In a multitrack setup, each part can be recorded independently, and the final result is mixed together from the best takes.
The simplest multitrack setup uses four tracks, allowing the singer, drums, bass and guitar to each have their own recording feed. A band can perform a take together, and any mistakes can be corrected by rerecording the part in question and mixing it with the pristine takes from the other members. Bands can also record each part in isolation, allowing each musician to focus on his own piece of the song without distraction. The completed song is then built at the mixing board using the best takes from each instrument.
The Beatles were among the first to mix together multiple four-track recordings, making eight-track recordings the standard by the 1970s. By the 1980s, 24-track recorders were common, and some bands even utilized multiple 24-track recorders to create extremely complex songs and audio effects.