From The Art and Popular Culture Encyclopedia
Multitrack recording ('multitracking' or just 'tracking' for short) is a method of sound recording that allows for the separate recording of multiple sound sources to create a cohesive whole. This is the most common method of recording popular music. In the 2000s, multitracking software for computers such as Pro Tools became widely used.
The process was conceived and developed by guitarist Les Paul in the 1940s with the financial and inspirational assistance of Bing Crosby and the Ampex Corporation, resulting in the first 8-track machine which used 1-inch tape. Through the 1950s, many popular recordings used the technology to enhance vocals by techniques such as overdubbing and superpose instruments. From these pioneering beginnings, it evolved in subsequent decades into a mainstream recording technique.