There are two ways a song can come to a conclusion. It can have a definite end, like a period at the end of a sentence. Or the song can just fade out as the chorus repeats over and over again. What’s the thinking behind this?
The fade is a technique that first started showing up in the very early 1950s when more and more recordings were made on the new-fangled magnetic recording tape. Tape offer much, much more control over the recording than the old-fashioned direct-to-master process. This meant multi-tracking, overdubs and, yes, fading.
Producers and artists believed that by repeating the chorus (or some other catchy bit of the song) and fading everything into silence did two things. (1) It gave the impression that the song never ended, that the party was infinite. And (2), the final round of repetition of the hook hopefully stuck in the listener’s head, prompting a more solid memory of the song.
Fading songs have gone in and out of style over the decades, but it’s still used quite a bit today.