Everyone is familiar with the words diva or prima donna, which have come to mean a (usually) outrageous operatic soprano, but there was a time when the star of the show was more often a contralto, or a soprano singing in today's mezzo-soprano range. This performer was referred to as an alto. In the 17th and 18th centuries, the male and female leading roles were likely to be sung by emasculated males, the alto castrati, although there were many great female altos during this period as well. The music for these fantastic artists, written by such composers as Porpora, Vinci, Hasse, and even Handel, has been largely forgotten. At the beginning of the 19th century, as the castrati died out, their roles were often assumed by female altos referred to as musici. New repertoire continued to be written for them by Rossini and others, but gradually, this musical tradition and technique was lost. Now, however, because of the talent and industry of such gifted artists as Marilyn Horne, Cecilia Bartoli, and Joyce DiDonato, and the sudden ease with which the performance of these forgotten works can be obtained, there is a resurgence of interest in the performance and preservation of this lost art. Alto: The Voice of Bel Canto examines the careers of nearly 320 great alto singers, including the great castrati, from the dawn of opera in 1597 to the present. The music of the composers who wrote for the alto voice is discussed along with musical examples and suggestions for listening. The exploration of the greatest altos’ careers and techniques offers inspiration for aspiring young singers as well as absorbing reading for the music lover who wants to know more about the fascinating world of opera.