Abnormally hightened sense of pitch perception, allowing one to do most (if not all) of the following:
* Correctly identify a musical note by name without any reference tone.
* Correctly sing a musical note at whim without any reference tone.
* Correctly identify the key a song is played in without any reference tone.
* Discern how sharp or flat a musical tone is,
relatively speaking, without any reference tone.
Also (more accurately) called
absolute pitch.
This ability, possessed by about 0.01% of the population, can be very helpful.......or almost useless.
No, you don't
necessarily have to be born with it.