I'm afraid to say too much about Thelonious Monk because I don't know a good-goddamned thing about jazz. I just, uh, "know what I like". Thelonious Monk, along with a number of other stellar musicians, was introduced to me by my husband David back in the late 80's, and he is my favourite among the jazz musicians that I am familiar with.
I just learned something interesting about him from good old Wikipedia: "Monk is the second-most recorded jazz composer after Duke Ellington, which is particularly remarkable as Ellington composed more than 1,000 pieces, whereas Monk wrote about 70". Something else that I am going to quote verbatim from Wikipedia that I found amusing:
"Monk had disappeared from the scene by the mid-1970s, and made only a small number of appearances during the final decade of his life. His last studio recordings as a leader were made in November 1971 for the English Black Lion label, near the end of a worldwide tour with the Giants of Jazz, a group which included Gillespie, Kai Winding, Sonny Stitt, Al McKibbon and Blakey. Bassist McKibbon, who had known Monk for over twenty years and played on his final tour in 1971, later said: "On that tour Monk said about two words. I mean literally maybe two words. He didn't say 'Good morning', 'Goodnight', 'What time?' Nothing. Why, I don't know. He sent word back after the tour was over that the reason he couldn't communicate or play was that Art Blakey and I were so ugly." It is surmised that he struggled with mental illness, which is not so amusing.
Anyway, to me he's the best so if you don't know his music you should check it out.