The two most common methods consist of In both cases, a new instrument, voice, or other material may be added with each bounce, depending on the setup's mixing capabilities.
The method was employed by Beach Boys co-founder Brian Wilson during the 1960s.
This meant that the album could not be suitably mixed in stereo, because the instrumental parts were locked in monaural.
In 1997, advances in recording technology allowed engineer Mark Linett to resync the original first-generation instrumental stems with the second-generation overdubbed vocals for the compilation The Pet Sounds Sessions and create a true stereo mix of the album.
[1] Ping pong is also a term of derision, in particular applied to early commercial stereo recordings of the late 1950s to mid-1960s which do not have a convincing stereo image or sound-stage.