This is a quote from page 365 of A Long Strange Trip by Dennis McNally
"In the middle of April they [The Grateful Dead] played a weekend at the Filllmore West that would be memorable for a feeling of utter silliness induced by following their opening act. Going on after hearing Miles Davis and the Bitches Brew band was, as Garcia put it, "ridiculous." "I don\'t ever want to hear anyone snivel about following anyone," said Lesh. "Because I got the one man, right there. Made me feel so dumb. I thought, \'What the fuck am I doing here, why aren\'t I at home digesting what I just heard?\' "