My current WIP game contains a music note collectible mechanic which allows players to play short tunes if collected in the right order (usually very obvious by the layout of the collectibles). So far, I've kept it at references to Mozart or Beethoven, as this is what fits my game's theme. However, I was thinking of hiding, say, the first few notes of the Mario theme, or of Star Wars' Imperial March, in certain locations, as an homage.
Is this copyright infringement? I assume that having a whole copyrighted song reconstructed note by note like so would constitute a breach of copyright, but how about 10 recognisable notes?