Dead. Where Is Thy Sting?

Why did the Grateful Dead playing live sound so terrible at times and at other times so spectacular according to audience recollections? Was it the amplification set-up? Quality of drugs available? Whether the band was rested? The crowd vibe? The venue vibe? Did the Dead themselves have a handle on this?

I am not a true DeadHead though I treasure the Garcia/Grisman recordings. Lots of my friends are Heads.Their stories of following the Dead around are full of legend  and calamity. They wouldn't have had it any other way. "Off" performances were just Part of Life. That's what they were looking for and preferred that it be unpredictable just like life.