Amadeus Revenge is a music-based shoot 'em up created by System Editoriale s.r.l. in 1988 for the Commodore 64. The game was developed using the SEUCK (Shoot 'Em Up Construction Kit).
In this game the player plays the part of Wolfgang Amadeus Mozart or Amadeus as he is known in the game. The goal of the game is to complete Mozart's famous Piano Concerto No. 25, (K. 503), referred to in-game as simply Concerto in C. To do this the player must navigate Amadeus across reams of sheet music while eliminating the conflicting notes produced by rival musicians. As a rival musician produces a conflictory note it is reproduced within the game score at the appropriate tone.
Source: Wikipedia, "Amadeus Revenge," available under the CC-BY-SA License.