Pierre-Laurent Aimard plays the first movement of Ligeti’s “Musica ricercata,” which uses the pitch class A (almost) exclusively. Watch until the end! Each subsequent movement of “Musica ricercata” uses exactly one pitch class more than the last, until the eleventh movement, which uses all 12 pitch classes. Aimard performs the complete “Musica ricercata” on his Artist Spotlight recital on November 7, as well as select Ligeti Études and the “Poème symphonique,” études by Chopin and Debussy, and b