Alan, the way iTunes is set up, a given song from the master Music list can be
on hundreds of playlists. Deleting one playlist should not affect a given song's
appearance on other playlists.

That said, I apparently work the same way you do. Each of my playlists is an
album, and no track on a playlist is duplicated on any other playlist. It is a bit
of a nuisance to wipe a playlist (album) then have to trash that album from the
master list.

But you don't have to put up with it in more recent versions of iTunes. Hi-Lite a
playlist and press Option-DELETE. That playlist and all its tracks are wiped.
Look at keyboard shortcuts under iTunes help and find other goodies.