esotery

1839 September 26, "Vindex," Letter to the editor, The Musical World, Number CLXXXIV [New Series no. XCI], Volume XII [New Series Volume V], May 23—December 26 1839, page 334, But a more important division of the musical public, is that of the learned and unlearned, the esoteries and exoteries ; and in no country whatever have I yet heard a perfectly educated musician call Mozart second-rate.

1954, William Bruce Cameron, Sociological Notes on the Jam Session, Social Forces, Volume 33, page 179, quoted in 2008, Paul Rinzler, The Contradictions of Jazz, page 54, This means, of course, a continual advance into abstraction and esotery, so that contemporary jazz is always musical casuistry, forever seeking new ways to rationalize the impossible.