A dipthong  - this is not a foolish man
Inappropriately dressed for sea or sand
Nor yet a verbal dipping, nor a thong
Nor yet a tropic river that flows along

A dipthong is two vowels in harmony
One with another dancing gracefully
Without a consonant to interrupt
Through a harsh, hinging sound that’s too abrupt

The poorly called but sweetly sounded dipthong
Is just another name for a little song