Topic summary
Music Track

Extracted from the Wikipedia article Album.
Tracks
Material (music or sounds) is stored on an album in sections termed tracks. A music track (often simply referred to as a track) is an individual song or instrumental recording. The term is particularly associated with popular music where separate tracks are known as album tracks; the term is also used for other formats such as EPs and singles. When vinyl records were the primary medium for audio recordings a track could be identified visually from the grooves and many album covers or sleeves included numbers for the tracks on each side. On a compact disc the track number is indexed so that a player can jump straight to the start of any track. On digital music stores such as iTunes the term song is often used interchangeably with track regardless of whether there is any vocal content.