Mr Fuse wrote:
Linda, some of the older stuff might not exist in anything beyond 4-track masters. I doubt that most record companies kept anything beyond the 2-track mix down masters for most albums with the exception of mega bands like the Beatles. I don't even think The Beatles recorded to 8-track until the White Album. I can't imagine making a good surround mix with less than 8-tracks.
The sessions for The Beatles were notable for the band's formal transition from 4-track to 8-track recording. As work on the album began, Abbey Road Studios possessed, but had yet to install, an 8-track machine that had supposedly been sitting in a storage room for months. This was in accordance with EMI's policy of testing and customising new gear, sometimes for months, before putting it into use in the studios. The Beatles recorded "Hey Jude" and "Dear Prudence" at Trident Studios in central London, which had an 8-track recorder. When they learned about EMI's 8-track recorder, they insisted on using it, and engineers Ken Scott and Dave Harries took the machine (without authorisation from the studio chiefs) into the Number 2 recording studio at Abbey Road for the band's use.
http://en.wikipedia.org/wiki/The_Beatles_(album)
