Grateful Dead

March 8, 1970 I was watching The Grateful Dead in Phoenix's Celebrity Theater (at that time it was still called The Star Theater), seating capacity 2650 and "in the round" with a revolving stage. The Dead were playing great that night, set list was ...Cold Rain And SnowYellow Dog Story China Cat Sunflower > I Know You Rider > High Time Dire Wolf Hard To Handle Monkey and The Engineer I've Been Around This World Me And My Uncle Black Peter Katie Mae > Impromptu Blues Not Fade Away > Turn On Your Lovelight When the band got to Impromptu Blues a guy walks on stage from the audience and starts playing harmonica at an open mic. I see Garcia and Weir shoot a look at each other and then shrug their shoulders and keep playing. This prompts the rest of the audience to walk onstage too and I ended up standing behind Lesh's amplifier with my arms resting on it and watching a minor miracle of hippie peace. No one mobbed the "stars" or disrupted the music. Everyone just danced or grooved and when the band asked everyone to return to their seats they did.