harmony

\ \ [14] The etymological idea behind harmony is ‘fitting things together’ – that is, of combining notes in an aesthetically pleasing manner. It comes via Old French harmonie and Latin harmonia from Greek harmoníā ‘means of joining’, hence ‘agreement, concord’, a derivative of harmós ‘joint’. As a musical term in Greek it appears to have denoted ‘scale’, or more simply just ‘music’, and its original use in English was for what we would now call ‘melody’. It was not applied to the combination of notes to form chords (a practice which originated in the 9th century) until the 16th century.

\ \ The term harmonica was coined in 1762 by the American physicist and statesman Benjamin Franklin for a musical instrument consisting of a set of water-filled glasses tuned to different notes and played with the fingers. It was first applied to the mouth-organ in the 19th century.