MUSIC NOTATION (1K ZX81)
by Ashley Robinson, Monks Risborough, Buckinghamshire
from Your Computer (December 1982), page 109

For those who have a limited 1K ZX-81 here is a little program which helps
you to learn notes in music. It does not play the notes, but displays them
on a treble stave.

When RUN it shows a treble stave with a random blob or note somewhere on
it. You have to press the correct note on the keyboard. It will then tell
you whether you are right or wrong and if you press another key it will
display another note.

It works by taking a random number and PRINTing AT that number on the Y
co-ordinate, a graphic square. It finds the answer by taking the code of
that number, adding 34, and finding the CHR$, which should be a letter from
A to G.

For those with 16K RAM packs you could make it play the note and display it.
