"Come and Go with Me"

Last week, I was thinking about "Come and Go with Me" (which I have only on the Sounds of Summer compilation album), and I realized a small thing about it:  "part" in the line "We will never part" is sung with a melisma (D B), so - although negated - there's a musical sense of that separation.

I referenced the version by the Del Vikings (which I believe is in the original), and while it's in a different key, it too has this feature.