I'm so sorry to hear this. Yes, he was an astounding musician, something that tends to get overlooked, in view of his pop successes and high-profile marriages to Dory Previn and Mia Farrow. I've admired him since high school (a looooooong time ago) when I had several rather low-key, offbeat recordings of him doing nifty things on a piano.

R.I.P. Mr Previn. Knock em dead up there. (Figuratively speaking...)