har·mo·ny 
(härmə-nē)
(härmə-nē)n. pl. har·mo·nies
1.
a. An orderly or pleasing combination of elements in a whole: color harmony; the order and harmony of the universe.
b. A relationship in which various components exist together without destroying one another: different kinds of fish living in harmony.
c. A relationship characterized by a lack of conflict or by agreement, as of opinion or interest: family harmony.
2. Music
a. The study of the structure, progression, and relation of chords.
b. Simultaneous combination of notes in a chord.
c. The structure of a work or passage as considered from the point of view of its chordal characteristics and relationships.
d. A combination of sounds considered pleasing to the ear.
e. A musical line that harmonically complements the melody: You sing the lead part, and I'll sing the harmony.
3. A collation of parallel passages, especially from the Gospels, with a commentary demonstrating their consonance and explaining their discrepancies.
[Middle English armonie, from Old French, from Latin harmonia, from Greek harmoniā, articulation, agreement, harmony, from harmos, joint; see ar- in the Appendix of Indo-European roots.]