 Aguilera's vocals on the song span from G#3 to E5.Its instrumentation comes from bass, cello, contrabass, drums, guitar, piano, viola and violin.It starts with a piano opening backed by strings and, as noted by Bill Lamb of About.com, "as the words work their way to a climax accented by percussion then gently fade away again leaving the listener in stunned silence from the beauty of the moment."