Pay attention to how the words of nursery rhymes feel in you mouth. Some words are right up in the front of your mouth and require precise movement of your lips and tongue while others are back in the throat. I contrasted two rhymes, Sing a Song of Sixpence and Dr. Fell. We would try to say Sixpence as fast as possible but also as precisely as possible. In fact, the rhyme begs to be said quickly. Quite the opposite is true of Dr. Fell, whose "l" and "o" sounds demand a slow tolling sound. My classes had a lot of fun with Dr. Fell since it was about a child telling off an adult in authority. We would say Doctor Fell "with menace" screwing up our faces to look as fierce as possible. British illustrations indicate that Dr. Fell is an academic, not a physician. In fact he may have been a professor of Classics at Oxford and the rhyme about the translation of a Latin text.
Sing a Song of Sixpence
"Sing a song of sixpence, a pocket full of rye.
Four and twenty blackbirds baked in a pie.
When the pie was opened, the birds began to sing.
Wasn't that a dainty dish to set before the king.
The king was in the counting house counting out his money.
The queen was in the parlor, eating bread and honey.
The maid was in the garden, hanging out the clothes.
Along came a blackbird and snapped off her nose.
But there came a jenny wren and popped it on again."
"I do not like thee, Doctor Fell,
Why it is I cannot tell.
But this I know and know full well,
I do not like thee, Doctor Fell."
(Don't forget to explain "Thee".)