5x5 Piston door - Minecraft 1.15.2 - Activates from any of 4 note blocks

This took me all day lol. I might make some improvements to it at some point, and maybe do a tutorial after that. For now I'm really happy with my first proper 5x5, I've tried many times and finally I got it :)

1.15,1.15.1,noteblock,noteblocks,redstone,hard,fast,opens,