Minecraft wiki entry for Development_versions, associated text: When placed on top of a bone block, wool, clay, packed ice or gold blocks, the noteblock produces no sound when altered or activated (this is to make place for new noteblock sounds coming up).
Added sound events (when using /playsound) for the following:
minecraft:block.note.bell
minecraft:block.note.chime
minecraft:block.note.flute
minecraft:block.note.guitar
minecraft:block.note.xylophone