What classical could be considered prog?

[gmknobl]

For purposes of possible play suggestion by the station managers, what music loosely defined as classical could be considered prog?

My immediate thoughts were:

1) Mysterious Mountain by Alan Hovahness (sp?)
2) roger.lee suggests Engulfed Cathedral by Debussey and I agree
3) Yes has used Stravinski's Firebird

Thanks!

P.S. This came from my thought that similar to some early big band being "rock" to my mind (ever listen to "Sing, sing, sing? The drum solo would be worthy of rock anywhere) there is classical that I think at worst is the inspiration for prog if not possibly an early form of prog.