Countertenors are male singers who specialize in singing in the alto vocal range. They are sometimes referred to as male altos, and the term 'altos' is a five-letter word that can be used to describe them. Countertenors have a unique sound that is often described as being between a tenor and a contralto. They are usually trained in classical music, but they can also be found in other genres such as jazz, pop, and rock. Countertenors are becoming increasingly popular in modern music, and their sound is often used to add an interesting texture to a song.