Ah, no... Such a great musician, sad to learn he's gone.
He's probably mostly know for soundtracks and new age-y ambient stuff for the general public, but he's had a huge range of work. Before becoming the solo synth artist, he was in The Forminx and Aphrodite's Child making early progrock. Then on synths, he made jazzrock (on Albedo especially - playing drums and bass himself!), heavily arpeggiated stuff (like Spiral), weird soundscapes (Beaubourg), operatic work (Heaven and Hell, Mask), poppier stuff (Direct, The City, Voices), actual pop (the four albums with Jon Anderson; rather hit and miss but some really good stuff here and there), numerous awesome soundtracks that are more mood-oriented (including especially Bladerunner and Conquest of Paradise; but there are tons of them, including nature documentaries like the amazing L'opéra sauvage), and a more layered rock-like album like See You Later, which is probably my personal favorite. And then I'm still forgetting stuff (e.g., China and Soil Festivities fit somewhere else again), and of course the actual rather ambient stuff (Oceanic, Rosetta - basically a lot of his work since the late 90s, that I am therefore also less familiar with).
Absolutely amazing and a great loss to music in my opinion. In addition to
@Sweet Square's and
@mazhar13's posts above, I'll just post what may currenly be my favorite track of his:
The arpeggiators, jazzy bits, beauty, sadness, even the collaboration with Jon Anderson: it's all there.