n.
 (pl. melodies)
 a sequence of single notes that is musically satisfying; a tune. 
▸the aspect of musical composition concerned with the arrangement of notes to form a satisfying sequence.
 ▸the principal part in harmonized music.
 
  Etymology
  ME: from OFr. melodie, via late L. from Gk melōidia, from melos ‘song’.