Harmony (noun)

1. A pleasing combination of elements in a whole.
2. An orderly and pleasing arrangement of parts; congruity.
3. A musical composition consisting of a sequence of chords.
4. A combination of simultaneously sounded musical notes to produce a chord.

Origin:

Late middle english: from old french harmonie, from latin harmonia, from greek harmoniā, from harmozesthai 'fit together, agree'. the sense "musical harmony" dates from the mid 16th century.

Examples:

1. The room was decorated in soft colors, creating a sense of harmony.
2. Her paintings have a sense of harmony between the colors and shapes.
3. The choir sang a beautiful harmony of voices.
4. The solo singer was accompanied by a piano playing a simple harmony.
5. The music was a harmonious blend of traditional and modern styles.