Countertenor
A countertenor is a male singing voice whose vocal range is equivalent to that of a contralto, mezzo-soprano, or (less frequently) a soprano, usually through use of falsetto, or far more rarely, modal voice. A pre-pubescent male who has this ability is called a treble. This term is usually used in the context of the classical vocal tradition, although numerous popular music artists also prefer employing falsetto.
Read more about Countertenor.