[MC-99529] Noteblocks don't play sound when a block is above them.

I tried to make a sort of timer with a visual and audible notification, and the noteblock would not make noise when there was a block on top.

Environment

Windows 7 SP1 x64, Java 1.8.0_25 64bit

This is intended and has been in the game since noteblocks were introduced.

has always been this way

I'm sorry for not being more specific, but what I meant is that it doesn't work with redstone dust or redstone blocks on top of it.

Still intended.