I don't like this smoke lots or 'shroom lots ... Is anyone absolutely positive he was hallucinating up on stage during shows? Or was this just a back-room thing?
In most cases, when I've heard musicians play out of their gourd, it sounded scattered and unfocused. There was far too much focus in the Dead band during playing to assume they were ALL actually PLAYING on drugs...
Before I go on my rant, beware I once considered myself a DeadHead (from 1971 - 2000). I have a lot of bootleg concert tapes, official releases and other memorbilia. I still go out to see them in their new bands when they travel through my geographic area, but I won't travel for extended distances anymore to see a show or a string of shows.
If you have heard them enough, you will find plenty of examples of them being scattered, unfocused and lost. It goes with their improvisational approach to the jams, especialy during the early days when they were also doing a lot of drugs. Weir, Garcia and Lesh all have an unique approach to their instrument. There were times at a lot of shows, when they were going in their own direction, they were not cohesive. I have heard them improvising on a one-chord vamp where Garcia and Lesh were playing different scales and Weir's chords did not fit the scales. Add to that the drummers and their improvising (especially Mickey Hart, Kruetzman is more of a pocket drummer), there are numerous times when no one, the musicians on stage or the audience, have any idea where the 1 was and how to get back to it. But all of this is part of the magic of a Dead Show: when they were off it could be really bad, but when they were on it was too good. The Phil and Friends line up has somewhat stabilized and from the concert recordings I have heard, they have become pretty cohesive. I look forward to hear how the remaining GD members sound together in the upcoming Dead reunion tour.
In regards to Phil's playing, I always thought he was so unique that I would not want to play like him but would want to learn a few good things that I could apply to my playing. I think the posters have already hit on these: he generally avoids the one unless it is a pocket song like Bertha, Shakedown Street, Touch of Gray, Truckin', etc. He likes to emphasive off-beat notes and non-root and (sometimes, not sure if that is always on purpose) non-chord notes. I believe he plays more from a scale perspective than a chord perspective. He has a bright sound, puts on new round wound strings before every show, has recently favored graphite necks and active electronics, plays with a pick and does not use a lot of effects. That new bass, a Ritter, if bizarre in appearance, but I have not had a chance to hear him play it so I do not know what it offers in regards to his sound.