The bassist is always the "musician's musician", and Dennis was that and a lot more. I remember seeing him with Scofield in the early 90s, and while fireworks went off everywhere in that band, he kept the ground soft for landing. Ethan's tribute is wonderful.
The Times obit is here. As I mentioned before in a post about Dennis and Andrew D'Angelo, in addition to supporting the worthy work for uninsured musicians Dennis' illness kickstarted, perhaps the best thing we can do is foment the real change we need so that everyone can get access to quality health care in this country.