Bug: Sometimes when noteblocks are playing, if you open a GUI, it does weird stuff like playing that note twice etc.

Steps to reproduce:
1:Make some kind of noteblock song, I suggest building like a loop with a scale, just to make it more clear.
2:Activate the song/whatever you built.
3:Open and close your inventory/any GUI (inventory just doesn't make any sound so you can hear the noteblocks) repeadetly.

I suggest you make a pretty long line of noteblocks.