Minecraft: 1.12 Pre-Release 5 Music Bug

Hello, My name is Koji and today i was playing Minecraft when pre 5 came out.
I started playing and my music was on so i turned it all the way down after i did that, it started playing again but very quietly.
So, since i turn it down to off, i can still here it so i think this might be a small bug, please fix thanks! - Koji