I've been listening to a lot of early 80's trash these days, as you can maybe tell. Anyway, it struck me that "Promises, Promises" sort of sounds exactly like Sugarhill Gang, a connection I hadn't considered. But then it turns out that this song actually copies from Captain Sensible's "Wot" (new to me, but they have a UK producer in common), and "Wot" borrows mercilessly from Chic's "Good Times", which I'd forgotten was sampled for "Rapper's Delight". So you know what that means: there's still basically three songs in the world, and Nile Rodgers wrote or performed the original version of all three. Stay lucky, I guess.