Tagged Notes
With this modification, you can customize note block sounds using block tags in data packs. To produce a special sound when playing a note block, simply place any block added to the corresponding tag underneath it.
The setup process is straightforward: create a data pack, add a block tag named in lowercase with underscores instead of spaces (for example, iron_xylophone). Then include the desired blocks in this tag and load a world with the data pack enabled.
Important: Fabric API is required for the mod to work.