Bernard Chasan wrote concerning editing technology

>No vodoo, just splicing in substitute patches.  I suspect that this
>was not done fifty years ago.  Perhaps it couldn't be done.

Not just patches, but pitches.  On the few occasions that I have
recorded my professional chamber choir, we were able to take single notes
from different takes to make a near-perfect splice.  It's really amazing.
In the old days of magnetic tape, you could of course, edit and splice,
but with nowhere near the incredible efficiency and accuracy that you
can accomplish with digital technology.

Kevin