My all-time favorite group! I always thought their stuff had much more depth, both music and lyrics, than other groups.
I've seen them live several times - always a wonderful show, and they still sound like they did 40 years ago (at least to me).
If you ever have the chance to see them, don't miss it. Also, if your PBS station ever broadcasts it, they did a concert at Red Rock, Colorado (I think that's the name). Outstanding. Might be able to find it on YouTube...
Oh yeah, and Justin Hayward did the music on "War of the Worlds", an album back in the late seventies or early eighties, with Richard Burton doing the narration. Great soundtrack. "Forever Autumn" - fantastic song!