One of the eight components of music, loudness has to do with how much energy an instrument creates when played, how much air is displaces. According to Levitan, loudness exists only in the mind. It is measured in decibels (dB). Loudness can be an important cue to meter and rhythms, as the loudness of the notes determines how they group rhythmically. (Sternberg, Barbara, PhD. Music & the Brain. p 8-10. CA: Institute for Natural Resources, Home-Study #2320, 2009).