You are all looking at the wrong words.
This old man, he PLAYED one.
It's about a musician.

"Nick nack paddy whack, give a dog a bone" is like Little Richard's

"Wap bop a loo mop a lop bam boom" (expained in his Biography), or the vocalised Tals that tabla players have to learn.

It's a drum beat- and a good groovy one too! The words have no meaning because they are actually vocables.
Cheers
Dave