There's some clever ways that one can code "The ABC Song". Here's a version that organizes the form via subroutines, uses conditional to capture the slight variation in rhythm, and loads all the lyrics into a heap to be called during musical playback.
Didn't think there could be so much in this seemingly simple tune, did you?
Check it out: https://youtu.be/nXXtJejUTCA
Try it: https://musicblocks.sugarlabs.org/index.html?id=1717202685037401&run=True