of, involving, producing, or characterized by harmony; harmonious

of, relating to, or belonging to harmony

of or concerned with an oscillation that has a frequency that is an integral multiple of a fundamental frequency

of or concerned with harmonics

a component of a periodic quantity, such as a musical tone, with a frequency that is an integral multiple of the fundamental frequency. Thefirst harmonic is the fundamental, the second harmonic (twice the fundamental frequency) is the first overtone, the third harmonic (three times the fundamental frequency) is the second overtone, etc

(not in technical use) overtone: in this case, the first overtone is the first harmonic, etc