I was writing symphonies, chamber music, string quartets. But when Nadia Boulanger analyzed my music, she complained that she couldn’t find any Piazzolla in there. She could find Ravel and Stravinsky, maybe Bela Bartok or Hindemith, but never Piazzolla. The truth is I was ashamed to tell her that I was a tango musician, that I had worked in the whorehouses and cabarets of Buenos Aires. Tango musician was a dirty word in Argentina when I was young. It was the underworld. But Nadia made me play a tango for her on the piano, and then she said, “You idiot! don’t you know, this is the real Piazzolla, not the other one? You can throw all that other music away”. So I threw away ten years work, and started with my nuevo tango in 1954.
– Astor Piazzolla
Cited at: http://www.tango.montreal.qc.ca/cbc/TANGOPT3/Tango3.html