I first ran into David at Albacon in 1998 where he was performing with the band "The Don't Quit Your Day Job Players". I heard him play again at Lunacon just a two Saturdays ago.
I credit David with turning me on to the Blues. I'd heard them before of course, but hadn't really fallen in love with it until I was exposed to his love of the music.
There's so many good things to say about him, he touched so many people, many of whom I count as friends also.
His LJ has a post with links to eulogies and tributes as well as a place for donations.
He leaves behind his wife Alexandra, services will be held this Friday in NYC, details can be found in the above link.