Every note is a sum of harmonic sine waves, usually not just a single one. The first harmonic of 440hz is 880Hz. So plucking a harp string for A4 will also prod

Every note is a sum of harmonic sine waves, usually not just a single one. The first harmonic of 440hz is 880Hz. So plucking a harp string for A4 will also produce the A5 and A6...