In short, there's not much of a secret, it's really just the result of the fact that we had to make up our own methods because multi-track voice production didn't exist when we started. Started out bouncing two track stuff - ping-ponging it was called at the time. You're exactly right, there had to be a track open for the old Elektra stuff, but it too could be bounced. with four tracks life was good. Eight seemed vast and on and on. So the early stuff is primarily based on getting the voice tracks done and then adding efx. Incidentally, Jac Holzman of Elektra later in life became an acquaintance, to the point that if you search my wife Oona on the web, you'll find her referred to - believe it or not - as a "lady of the canyon" in Jac's autobiography or something.