melody

n.

1. The quality of being melodious

   consonance, assonance, concord, unison, euphony, resonance, inflection, chime; see also harmony 1.

   Antonyms noise*, discord*, disharmony. *

2. A melodious arrangement

   tune, air, song, strain, theme, line, descant; see also music 1, song, tune.

melody refers to a rhythmic arrangement of tones in sequence expressing a musical idea; air, in strict application, refers to the principal, or leading, melody of a harmonized composition, but it is sometimes used as an equivalent of tune, which is the popular term for any easily remembered melody that identifies a song, dance, etc.