La Belle Histoire d'Amour possibly?
you'd think, wouldn't you? but it wasn't that one. the one i'm thinking of probably wasn't a torch song. in fact it was almost light-hearted by her standards and it might have been, or been derived from, a folk song. it had a much more folk-music sound/structure/pace/theme. somehow i have the impression it was a narrative rather than just a 'mood', and that the narrative was about two people neither of whom (for a wonder) was her. i really thought it was mon legionnaire until i found out i was wrong. but i think it was that kind of story - girl, soldier, battle, etc. the chorus had a sort of upbeat marchy kind of rhythm. the first line of (the chorus) was a bit like the first lines of la brindisi http://www.youtube.com/watch?v=z1ohegoq_IA, from la traviata. the same lift. man, i suck at trying to discuss music.
i don't mean to diss piaf, saying all that. i like her voice a whole lot. i guess torch just isn't really 'my' genre.