Jimmy Scott – Jazz singer with Kallmann syndrome.

https://en.wikipedia.org/wiki/Jimmy_Scott

Jimmy Scott might not have been a household name but he was well known in the jazz music world due to his distinctive voice. He was known for a strong contralto voice, which is normally only associated with female singers.

He had Kallmann syndrome and refused to have testosterone treatment for most of his life to prevent his voice from breaking to preserve his singing ability. He was one of the very few known natural castrato professional singers.