Peter & Gordon's "My First Day Alone"

Yester-day I listened to a compilation album of Peter & Gordon, and I noticed something about the harmonies in "My First Day Alone."  For much of the song, both Peter & Gordon are singing, but during the line "no one's to blame but me," one of them (I'm pretty sure it's Peter) drops out so that the other (Gordon) sings "but me" alone.  Because there's a single voice for that "but me," the exclusivity of the blame is represented musically.