improvisational music should not be recorded

Summertime.  Uncertain reassertion of degrees of normalcy in pandemic times.  While pondering my treatise on the merits of the JGB circa 1976, I was distracted by my record collection and, for no reason whatsoever, pulled out Miles Davis' Filles de Kilimanjaro to have a gander at it.  I looked at the liner notes on the back and did a doubletake when I saw that Ralph J. Gleason namechecks Dannie (sic) Rifkin, "longtime student of improvisational music" -- or, to you and I, manager and family member of the Grateful Dead.  Besides Danny Rifkin, Gleason quotes Gil Evans, André Gide, Edgard Varèse, and David LaFlamme in his assessment of Miles' latest directions in music.  I am not sure what to make of that.

Rifkin seems to have been slightly overshadowed by other personalities in the Grateful Dead story, but a cursory look at the literature reminded me that in addition to managing the band on and off through the decades, he was the guy who originally managed the house at 710 Haight-Ashbury, instituted the Dead's mail-order ticket service, and spearheaded the creation of the Rex Foundation.  But a manager of the Grateful Dead saying improvisational music should not be recorded but only heard once?  Say it ain't so.