I'm starting to enjoy the analyze-the-tone game, so here's my contribution
Favorite tune of mine, early 70's progressive stuff from Vangelis' first solo album. This is interesting to me because I go for a fairly clean modern tone and am just really starting to appreciate the bass tones of yore
http://www.youtube.com/watch?v=sYXL2WwQn1I
The bassline is obviously very repetitive but it serves the song well. It only changes at 2:21 when he switches up the groove with a quarter-note figure that i think is just brilliant.
I'm really curious to break down the tone too - not that I'm trying to get it, but just for fun. I'm thinking P-Bass with a pick for starters and definitely some EQ in the high mids...