Robert Anton Wilson, a jazz buff, was a fan of the Modern Jazz Quartet and saw the band live in the 1950s, when jazz in the U.S. arguably reached an artistic peak. From left: Percy Heath (double bass), Connie Kay (drums), Milt Jackson (vibes) and John Lewis (piano). (Public domain photo).
Prop Anon on Twitter: "First time #RobertAntonWilson smoked weed was during the intermission of ModeRn Jazz Quarter show back in the Fiddies in NYC
"The Xylophone never sounded so good."
Eric Wagner also discusses this in An Insider's Guide to Robert Anton Wilson. In fact, Eric has a separate entry on the Modern Jazz Quartet in the book's Lexicon section. (I keep a Kindle copy of the book on my smartphone so I can refer to it easily. I'll probably do the same thing when Prop's book comes out.)
Does anyone know if RAW saw any of the 1950s incarnations of Miles Davis' band?
Wikipedia has a nice entry on the Modern Jazz Quartet.
Bonus music bit: Nice photo of the MC5 on Twitter, a band mentioned in Illuminatus!