nostr:npub1d7v8h9rnl45p7ar7n55hay4706xfhaty4tpa4tpr5azlm5xnl63su3eut5 - great!  They may like this too!  

For more details (and possibly iideas for exercises) go here:

https://en.wikipedia.org/wiki/Tonnetz

https://media.mathstodon.xyz/media_attachments/files/111/177/088/910/555/474/original/e1a06be1043b379b.mp4