Do you have a piece of music, song, or musical performer or more than one that you consider a "hidden treasure," one you came across off the beaten path and love but nobody you know has ever heard of?
Here are mine:
Glenn Gould playing the Franz Liszt transcription of Beethoven's Fifth Symphony. To hear that entire symphony on piano only, as only Liszt could have transcribed it and as only the Great Gould could have played it should be heard before you die.
Mahler, Songs from Ruckert, conducted by Leonard Bernstein and sung by Dietrich Fischer Dieskau. There's also a piano only accompaniment recording with Bernstein at the piano. The songs are really notable for only one song, "Ich bin der Welt abhandon Gekommen" ("I Have Lost Track of the World"), which is said by some to be the greatest piece of music ever written. I won't argue that, but if you get a conductor who knows what to do with the crucial chord, it can rip your heart out.
Alban Berg, Violin Concerto, Yehudi Menuhin on violin. I know, atonal. But Berg is wonderfully "tonal" in this piece subtitled, "On the Death of an Angel" and dedicated to a friend or relative's lost daughter (sorry, my vinyls are in storage). Don't even both listening to anyone but Menuhin play this. I had three recordings at one time. It's not even the same music without Menuhin's genius.
"Copulatin' Blues" I think this is on Rhino Records. It's a great collection of blues and rags from the early 30s, with great performers such as Bessie Smith. The songs are all double entendre about, well, copulatin'. "Press My Button, Ring My Bell." You get the idea. It's just naughty fun, but don't hunt down if you're shy about such things. "Tea Time Rags" would be more up your alley--whoops, they ain't singing about that kind of tea.