from a single original master recording, which might itself be based on previous recordings. For example, sound effects (e.g. a door opening, punching sounds, falling down the stairs, a bell ringing) might have been added from copies of sound effect tapes similar to modern sampling to make a radio play for broadcast.

Problematically, several different levels of masters often exist for any one audio release. As an example, examine the way a typical music album from the 1960s was created. Musicians and vocalists