Time and rhythm is such an important part of music making. Maelzel's Metronome mark (M.M) is still used in pieces today despite being created nearly 200 years ago!This would look great on top of my Steinway :-
This was the first ever keyboard I owned, and when I started piano lessons this was what I had to practice on.
It actually sounded nothing like a real piano, but boy, did it help get me using my imagination.
In my teens I remember recording songs on one of these! It was a pretty expensive piece of kit for an amateur.
You could slow the speed of tape up or down to sing a harmony you couldn't reach. Happy Days.