What a primo example. It's not about "quantizing", is it? In this song (as well as yours) there is syncopation, and singing "against" (as opposed to completely along with) the pulses in the piano rhythm. The earlier in the songwriting process you can get that "feel", the better--no matter how you tend to write. In Floyd's song, the rhythmic groove (especially at his tempo) was wide, and he "surfed" it just as she did here...but he never went over the edge, and I've not heard him do it yet. Carole King didn't sing every parallel phrase exactly the same way...and I've heard other performances that were "phrased" differently. But no matter how she chose at the moment or in rehearsal to do it, it's right and "feels" right. And it's right because she wrote it that way.

My go-to example is James Taylor's "Mexico".

Another good "method" to get this into your soul is to listen to the bass, if it's an active bass-line. Latin, Funk, whatever if it is much more than thump-thump-thump. WHERE (when) the bass licks hit, how hard, and how long they hold is maybe even more important than what notes are hit. Same with a vocal in most popular music. As long as it remains musical, the rhythm of the vocal supersedes the melody even if it doesn't replace it.

When melody, words (and their melodic delivery), and the rhythm of the vocal all work together...that's a good song--even with just a piano or guitar accompaniment. I'd agree with Floyd...the most important of those elements is the rhythm of the vocal.

BIAB 2021 Audiophile. Windows 10 64bit. Songwriter, lyricist, composer(?) loving all styles. Some pre-BIAB music from Farfetched Tangmo Band's first CD. https://alonetone.com/tangmo/playlists/close-to-the-ground