"The Right Girl", "Too Many Mornings" (though it's a duet, and plenty longing is coming from Sally, Ben is the one who introduces the regret), "Buddy's Blues" - FOLLIES
The first of these starts as a frantic up-tempo, but about 2/3 of it is a slower kind of frantic, if that makes sense. The second is pure ballad, enjoy. The third is a purely manic up-tempo. All are crushing within context.
"All Through the Night" - ANYTHING GOES
Not too heavy, but pleasantly melancholy.