 Other themes include trying to pursue a relationship , as well as trying to make a relationship last , which can be seen in the lyrics , " I know you 're leaving in the morning , when you wake up / Leave me with some kind of proof it 's not a dream " . According to the sheet music published on Musicnotes.com by Alfred Music Publishing , the single is written in the time signature of 12 / 8 . The song is played in the key of B Mixolydian and is sung in the vocal range of F # 3 to D # 5 . " The Only Exception " has a moderately slow tempo of forty eight beats per minute . 
