There’s a plethora of duet albums these days. Most of these seem to involve one singer taking the first verse, another the second verse etc.
But how many songs can you think of where there are two distinct characters singing?
Very common in opera and musicals of course, but less so in pop and rock.
I’ll kick off with Ms Lauper and Howlin’ Pelle getting into quite a lively Xmas row where quite a few skeletons get thrown out of the closet.
https://www.youtube.com/watch?v=3fdj5m1DEs0