Look up: Overdubbing

1. Overdubbing
   1) Adding additional musical parts on a track of a multitrack tape.
   2) Sending a previously recorded signal through a console and mixing it with the audio from a new sound source, recording onto another tape.
   Found on http://www.testing1212.co.uk/a.htm
   
   
2. Overdubbing
   Enables one or more of previously recorded tracks to be monitored while simultaneously recording one or more signals onto other tracks. This process can be repeated until the song or soundtrack has been built up. If a mistake is made, it is possible to recue the tape to the desired starting point and repeat the process until you have the best take on tape. See Dubbing
   Found on http://www.musiconmypc.co.uk/art_glossar
   
   
3. Overdubbing
   `Overdubbing` (the process of making an `overdub`, or overdubs) is a technique used by recording studios to add a supplementary recorded sound to a previously recorded performance. Tracking (or `laying the basic tracks`) of the rhythm section (usually including drums) to a song, then following with overdubs (solo instruments, such as keyboards or guitar, then finally vocals), has been the standard technique for recording popular music since the ...
   Found on http://en.wikipedia.org/wiki/Overdubbing
   
   
4. Overdubbing
   `Overdubbing` (the process of making an `overdub`, or overdubs) is a technique used by recording studios to add a supplementary recorded sound to a previously recorded performance. Tracking (or `laying the basic tracks`) of the rhythm section (usually including drums) to a song, then following with overdubs (solo instruments, such as keyboards or guitar, then finally vocals), has been the standard technique for recording popular music since the ...
   Found on http://en.wikipedia.org/wiki/Overdubbing