natural harmonics

Noun

natural harmonic (plural natural harmonics)

1. a sound produced by lightly touching the string as opposed to pressing it against the fingerboard, usually with the actual pitch notated
2. The series of pitches produced by a wind instrument without modulation by a mute, valves, or keys.
   • Although stopping may have served to produce some chromatic sounds, and partially filled up some of the smaller gaps in the natural harmonic series, the characteristic clearness of trumpet-tone was largely lost when the instrument was thus muted by having the passage through the bell closed by the...1939, Adam Carse, Musical Wind Instruments, →ISBN, pages 235–236