Music playing trough each other.

I was just playing some Minecraft as usual.
Describe what you thought should happen here

And then in the Main Menu and in game i heard 2 music tracks through each other. And it does'nt sounds good! I think it was The new music playing first. And then the old music after 10 seconds while the new music was still playing.

Its not realy a procedure. You just need to listen to the music. That's it.

B.T.W.: Sorry for my English. Its not my mother language.