The most musically complex prog band(s)?

A few posts back Camel was getting some flack for not being "complex". While I agree with the comments that were said(musics not hard to play...) I think its necessary to exclude Andy Ward. I always thought his percussions were "technical" enough to called "complex"(If that makes any sense) Not only that, but he has worked with other bands that were thrown in the "complex" catigory, i.e Marillon and Caravan. So lets at least here for Mr.Ward.

This is all a bit of a t**ser. The only way you can judge complexity is at a playing level, not a listening level. That is- which grade would they be placed in at a music examination level: Grade 1 (easiest)  to Licentiate (most difficult, with a very small percentage of players being able to attain the skill needed to play them). Of course band music has the added problem of being group music, so there are other considerations of how to rate them such as contrapuntal problems (is it easy or extremely difficult for the group to play this together and keep the timing true). A good example of this may be certain Yes songs, which have 4 instruments playing completely different parts that come together as a whole in some strange magical meld, that are not that difficult to play as solos, but putting the four parts together and in time adds to the difficulty of the piece, astronomically.

So how do you judge music complexity?

Except GENTLE GIANT and YES of the TFTO album,try YEZDA URFA...you'll be blown,that's really complex but creative music!