Hop Hop Top

The rhymes in 'Hop On Pop' are so catchy and memorable. I'm curious whether the rhythm was planned from the start or developed during writing.

The silly scenarios really engage kids while subtly teaching words. Did the humor come from a desire to make reading enjoyable or from a love of wordplay?

As a children's classic, it seems to have stood the test of time. I wonder what the initial reactions or challenges were during its early days.