Heh! Listing to the Grateful Dead from the evening of 2 March 1969 at the Fillmore West. Right in the middle of the “Drums” part of “Alligator > Drums > Jam > Caution (Do Not Stop on the Tracks) > Feedback > We Bid You Goodnight”, what do Mickey and Billy break into? “Ketjak”! (You know—the Ramayama Monkey Chant.) It is to laugh!