On pop music it is often that the singer begins notes before the beat

For example:
Forever J - Terry Hall (Just heard this on Easy 97.2 FM)
https://m.youtube.com/watch?v=rF78zx6a3bk


A way to hear this is taping 1 2 3 4 while each bar of the song plays.
Or taping each of 4 fingers at the time, index finger tapping for example 1 ie each beginning of a musical bar.


Then we can see that many sung notes begin before 1 ie before the beginning of a bar.
And some words begin exactly at beginning of a bar.
This irregularity creates a very interesting contrast.