Related Clues:
- Vowels in "Old MacDonald"
- Last three letters of a farmer song refrain
- Refrain in 51-Across that accompanies the sounds at 24-, 37- and 47-Across
- All-vowel refrain in a kids' song
- Refrain in a song with the words "With a moo moo here"
- Singalong quintet
- Children's song refrain that's all vowels
- Letters preceding "with a moo-moo here"
- Nursery refrain