Oh my god, I can't handle so much nostalgia. I remember playing this when I was a kid, and this theme is burned in my head ever since. Way, way better than the SNES music for me...
There's probably a good reason for that, and said reason could be that it might not have been composed when the SNES version came out in 1994. Either that, or it was originally going to be for a Game Boy Battletoads game that was cancelled when Donkey Kong Country came out.
Several levels they used the music from Donkey Kong Land. This level wasn't from any Donkey Kong Land or Donkey Kong Country. Did they just make this one up ?