I really thought (and hoped) this was a hoax when I saw it late last night. I didn't even know he had been ill. It's hard to believe such an influential musician is gone. I think my introduction to him was his singing "The Little Drummer Boy" with Bing Crosby, but I loved his "Serious Moonlight" phase the most, I think.
He did any kind of music he wanted- rock, art stuff, pop, jazz, and despite him always re-inventing himself, he was still always Bowie. This is from 1990, and also features the amazing Adrian Belew on guitar. RIP David Bowie, often imitated, always original.