The countertenor voice is a fully intact adult male alto or soprano singing with what, unfortunately, is called “falsetto.” There’s nothing false about it. Every adult male confident of his masculinity is able to produce this sound , as it consists simply of vibrating the inner edge of the vocal cords rather than the whole vocal cord. Only in the last decades of the past century have voice teachers, conservatories, and operatic training programs accepted the solo countertenor voice as a legitimate Fach (vocal category) worthy of technical development. While countertenors have been used for alto parts in all-male church choirs since at least the seventeenth century, the solo countertenor is a relatively new arrival in modern performances of opera and oratorio. Chorally-trained English countertenors sang in a rather hooty, one-vowel-fits-all tone quality more suitable for the austerity of Renaissance sacred music than the heroic display required of Baroque dramatic roles. Operatic countertenors today are cultivated to produce a brighter focused sound, with technical agility and strength necessary to be heard over an orchestra in a large hall. They say that hell hath no fury like a mezzo-soprano hearing a countertenor sing a role traditionally assigned to her. The incursion of countertenors into the alto solos in Handel’s Messiah in the 1970s established a beachhead from which they have proliferated today into the entire dramatic repertoire of the seventeenth and eighteenth centuries. Because of the affinity for high voices by audiences in the gender-bending Baroque period, impresarios–both then and now–mix and match genders according to their vocal ranges and box-office appeal, not necessarily according to the sex of their role.