However the idea that subversive original work is "avantgarde" music seems like an overly inclusive definition of Avantgarde that it becomes a meaningless term. I mean virtually every musician that is considered original (as originality is inherently subversive) would fit the definition even if no one would classify them to be avantgarde
Bob Dylan is avantgarde because his music was original in synthesising poetry and folk music with rock music and added a literacy to rock music. His unique and unusual voice also expanded the definition of what is considered a good vocalist. He was also subversive in trolling his audience during his electric years. However he is never classified as Avantgarde
Mozart is avantgarde because his opera was original in creating continuous dramatic motion in his music. His opera's was subversive as Marriage of Figaro is essentially class warfare at the aristocracy and mocked the very group of people who funded and paid for his career and Cosi Fan Tutti was considered immoral, sexist, raunchy and vulgar opera back in the day. However apart from people using avantgarde as an adjective (avantgarde like work due to it's originality) he is never classified as an avantgarde artist
I guess with originality and subversiveness. Every important artist is an avantgarde artist that the term is meaningless to distinguishing one artist from another
From wiki when looking at the list of Avantgarde artist "The term is used loosely to describe the work of any musicians who radically depart from tradition altogether. By this definition, some avant-garde composers of the 20th century include Arnold Schoenberg, Charles Ives, Igor Stravinsky, Anton Webern,George Antheil (in his earliest works only), Alban Berg, Henry Cowell (in his earliest works), Philip Glass, Harry Partch, John Cage, Morton Feldman, Richard Strauss (in his earliest work), Karlheinz Stockhausen, Edgard Varèse, and Iannis Xenakis."
Apart from Richard Strauss I think pretty much all of them to be music not really meant for pleasure or entertainment. It seems silly to bracket Beach Boys, Can or Devo with them. Let alone Mozart, Dylan etc