Gamemode switching turns off music!

So I was in 14w11b and some music started playing, nothing unusual, but when I decided to test something with redstone I switched gamemodes. And the moment I pressed enter to execute the command /gamemode 0, the music just stopped! Later it started playing music again, by that time, my redstone testing was over, so I switched to creative. AGAIN, the music stopped!

-I don't know if it's switching to all gamemodes, I just found out creative and survival!

-I was in a super flat world with redstone ready preset.

This is all info I have.