I'm really glad you liked the music!! Although if Meteo's whistling wasn't obvious, I guess I might have to simplify the music some more :D
Building up the music as you collect notes sounds interesting on paper, but in the game it would likely be at the cost of clarity for the puzzles. If a note can't occur (or occurs less) when it isn't collected yet, it becomes more difficult for the player to know if the note fits. It's an idea I fiddled with, but decided not to use. Collecting more dinos would be fun though, I'll definitely write that one down!