Just to keep the conversation lively, here are two pieces for which I'd gladly pay a premium to obtain a good multi-channel recording:
The first is Respighi's "The Pines of Rome." The first time I heard this piece performed, the orchestra included 5 or 6 small brass choirs spread around the various corners of the theater. Talk about surround sound! The effect was, um, really effective! Capturing that kind of a performance in full surround would be a great way to show off the capabilities of multi-channel audio.
The second is one of Zappa's final concerts where a live ensemble performed "The Yellow Shark." It was presented in 6-channel surround, with speakers at the front L&R, center L&R and rear L&R of the audience. In addition to the main mix, Zappa used little costumed guys with fishing poles to lower hula hoops over the heads of soloists. The hula hoops had 6 mics positioned around the hoop which sent the solo out to the various corners of the PA system. I've always wanted to hear that one in surround...
