Hrm, album recorded in 1979, but you're right; In the USA, 'twas the #1 single on Billboard's chart for the entire month of June, 1980.
So, no accounting for time-to-market, release date, etc., and I have my foot stuck in my jowl again.
I can still hear the synths.
Man, what I wouldn't give for a Prophet-5 ... or maybe even a Juno 105.
Though I'd no idea what I'd do with it. Digital synths are so much more practical. But the sound.... 🙂