While straight up disco can be a bit limited in scope for my tastes, adjacent terrain has some real gems to offer.
It would have been foolish to underestimate Japan even in 1976:
The corresponding
album by then 17-year-old Japanese idol singer Hiromi Iwasaki has to be one of my very favorite discopop affairs ever. Her little sister Yoshimi had a few nice albums in the early '80s, too.
Another one of my faves in a similar vein is a few years newer and by a then still rather young Junko Yagami, already complete with her legendary "aahs":
Japan had some really cool genre mixes going at the time that you rarely find anywhere else (the closest I got to something similar to city pop from the Western hemisphere was a rather obscure album by Canadian singer Patsy Gallant).
That reminds me of another good one, the brilliant Haruko Kuwana, here in a rare TV appearance:
The album was actually recorded on Hawaii if memory serves.
On a global scale, the mid-late '70s have to be pretty hard to beat music-wise.