Blame my friend, but he found these DVD(A?)'s on the Internet of some previously unreleased Quad mixes of Dark Side of the Moon and Wish You Were Here.

DSOTM is definitely better sound quality wise than WYWH. I haven't heard the SACD version of DSOTM so I can't compare to it, but the mixes treat the rear channels the same as the front. In fact its the first time I have thought my QS4's were definitely not what I need to properly listen to these. (I think the bigger issue is the placement of my surrounds is far from idea for multichannel music)

I'm pretty geeked to have these thou. According to the threads on AVS Alan Parson's did the DSOTM at least. It was recently converted to DVD-A I guess. I don't have a DVD-A player but it sounds great in DTS (and DD).