Us and Them
It's sad to hear that Richard Wright has passed on. It's is the end of an era in music, since he was integral to the classic sound of Pink Floyd. I was often astonished by the list of musical instruments he played on various tracks, although he was never accoladed as much as other members of the band. He had a strong hand in some of my favourite songs, most notably "Us and Them", which ranks in the upper echelons for me.
Much of his musical work was extended, that is to say significantly longer than the 3 minute mark considered acceptable for radio airplay. "Interstellar Overdrive" ran nearly 10 minutes. "Careful with that Axe, Eugene" and "One of the These Days" are both over 5 minutes. "Us and Them" is close to 8 minutes, although a 4 minute single was released. You get the idea. To anyone that thinks Pink Floyd had an easy string of hits, realize they often did it outside of the mainstream, but still managed to encompass it.
He was a leader in textured modern music, influential in the same subtle ways he blended ethereal ambiance into songs. We have many more choices in these areas now, there are various entire genres filled by bands like Sigur Rós, Massive Attack, NiN, Les Claypool, etc.. I have no doubt Richard Wright influenced many of these in direct and perhaps more importantly indirect ways, after all he was skilled at layered backgrounds that somehow retained simplicity.
I'm a fan, what can I say? It's a shame we won't be hearing more from him.

