system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What determines whether or not someone is a naturally good singer?
gpt
Physically speaking, being a naturally good singer means you were born with a good "instrument". Your vocal cords would be more elastic and flexible, and this would make your voice able to produce more overtones, or the right mix of overtones which sound pleasant. Overtones are basically sound waves on top of sound waves which have wavelengths that overlap on the original wave, e.g. half the wavelength, one third the wavelength, and we can tell the difference between a trumpet and a piano or a sweet and a shrill voice largely by picking up on the differences between the mixtures of overtones. 


Besides that, being naturally coordinated would help controlling the muscles which keep a steady pitch or vibrato or volume, being naturally gifted in pitch and tone differentiation would be important(good ear, perfect pitch), and because IMO natural abilities get a little too much credit with the general public, a natural patience, memory, intelligence, passion and persistence would all be very important when it comes to learning and practicing. Because no one comes out of the womb singing.