I think note blocks should be crafted with amethyst

Because we know amethysts make sound when they get punched or walked on.

By covering it with planks, makes them more preserved that they only make sounds when they get punched or change the sound every hit, and they change the tone of the sound any block they are below, because amethyst is a crystal, it echoes the sound and trap the sound the block under them and make them leave the sound of the block under.

And by making the crafting recipie like this, gives the amethyst more use.