In-game music... sure, there are some masterpieces around, but I'm quite sure that you'll have at least one or more songs that you can't really stand... that kind of music so terrible that it makes you want to turn off audio when you hear the first note 
For me, it's definitely this French song... well, I think it's French because it was included in no less than a million of MSX1 games and they were all made by the same French company; it's a song composed with no more than ten or twelve notes, that are repeating *FOREVER*. It doesn't matter if you were playing as a firechief saving people in a house, or as a denture avoiding candies in a labirynth, you were always forced to hear this music. Still today I have nightmares at night because of this song 
-> Hear the music <-
, I believe it's not a french tune, IIRC it's a dutch one......isn't it the Bytebusters jingle?. A little repetitive; but not bad so far...
