To answer the thread title

The Music

As Benny Green (if you now, you know) came up with the immortal quote

Song lyrics are rubbish, absolute tosh.
Until you marry them to the music.

Of course he was a musician and DJ. Not a poet or story-teller. So we have to factor-in the listener. (s)he makes it a hit!

Yea there are techniques. Vowels are soft and full of luuuuurv. Consonants like "K" are funny, especially if alliterated. Rhyme telegraphs the punctuation and give the listener time to extract meaning. It also fires the endorphins as a reward for not quite predicting the word. We could go on, but as George Bernard Shaw said:

the golden rule is, that there are no golden rules to which I would add if used wisely