That expression always conjures up for me in my mind pictures of "The Dying Swan" ballet scene to the wonderful music of Saint-Saens -
The Dying Swan

However, hysterically mixed with the picture of the all-male Ballet Trockadero's version with the poor old swan losing all his feathers one by one! Do watch this clip to the end!
Dying Swan - Les Trocks

Sorry, I know this thread was supposed to be about passe singers:can think of a few, but won't name them just now! Going through it myself just now, as my hearing deteriorates to the point that I no longer have that all-important feedback between mouth and ear.