A remix is a piece of media which has been altered or contorted from its original state by adding, removing, or changing pieces of the item. A song, piece of artwork, book, poem, or photograph can all be remixes. The only characteristic of a remix is that it appropriates and changes other materials to create something new.

Multitrack recording (MTR), also known as multitracking, is a method of sound recording developed in 1955 that allows for the separate recording of multiple sound sources or of sound sources recorded at different times to create a cohesive whole. Multitracking became possible in the mid-1950s when the idea of simultaneously recording different audio channels to separate discrete tracks on the same reel-to-reel tape was developed. A track was simply a different channel recorded to its own discrete area on the tape whereby their relative sequence of recorded events would be preserved, and playback would be simultaneous or synchronized.