Here's an idea for a hypno file. The file could install a trigger which would make the subject forget the musical content of a specific piece of music. This way, one could forget about an old song which has become boring over time and like the music as much as during the first listening. The trigger could even be made to work on all the songs on one's MP3 player.
I came up with this when I was walking home, listening to my MP3 player. I don't know if such a file already exists elsewhere, but there seems not to be one at WMM.