Sergei Prokofiev described Stravinsky's neoclassical works as "Bach on" these things.
During a 2012 Diamond Jubilee concert, pianist Lang Lang added a prominent one of these things to a cadenza in Rhapsody in Blue. D sharp, F sharp, and A sharp are the first three of these things in a work whose Vivace first section precedes a Più lento B section that seemingly lacks them. Apocryphally, Charles Ives responded to comments that his Country Band March had "so many" of these things with the rejoinder "You're quite right. It's perfect." Sergei Prokofiev described Stravinsky's neoclassical works as "Bach on" these things. These things make the singer "doo doo doot" in a namesake "rag" that describes "a new sensation that's goin' around" from the musical Wonderful Town. These supposed things nickname the E-minor opus 25 No. 5 étude by Frederic Chopin, due to its rapidly-resolved 9ths and other dissonances. For 10 points, name these musical events, such as a flautist playing a D instead of a C.
During a 2012 Diamond Jubilee concert, pianist Lang Lang added a prominent one of these things to a cadenza in Rhapsody in Blue.
wrong notes [accept clear equivalents such as incorrect notes; accept ‘Wrong Note’ étude or The Wrong Note Rag; accept extra notes before “Vivace”; prompt on dissonances or minor seconds or minor ninths or grace notes or acciaccaturas or sixteenth notes by asking “Which result from what things or supposed things?”]