Playback location   

The process of playing back prerecorded material during a film shoot for synchronization purposes.
Often used in music videos to facilitate lip sync and performance gestures, etc. during filming. A composer may also specify playback during (for example) a dance sequence so that actors can move to specific rhythm and/or tempo.
Playback device must be precise enough to insure speed and pitch will match that used in post production process (i.e. either a Nagra with Pilot tone or a DAT).