While we're on the subject of music, that was my favourite thing about Gen I and II, no contest.
Gen II was great because the music during battles actually felt like an upgrade, as opposed to something in the same vein (despite loving Gen V I actually really dislike most of the battle music, and consider Gen VI's music the only worthwhile part of the game).
Gen I trainer:
https://www.youtube.com/watch?v=3qp0kAobGrsGen II trainer:
https://www.youtube.com/watch?v=JbCtVIDMEAs 