Syd Barrett, dead at 60.
David Bowie, from the linked article: "His impact on my thinking was enormous. A major regret is that I never got to know him. A diamond indeed."
See also the BBC's obit.
Some hand in hand
And some gathered together in bands
The bleeding hearts and the artists
Make their stand
A fond farewell; the world is sadder and less strange today. Wish you were here.
(Hat-tip to Antiprincess, on whose site I read the news.)
Update: Read this too. Heartbreaking and lovely.