There are several voice type divisions.
Leggiero/soubrette ('light' and 'cunning or shrewd' - a comedienne)
Famous roles: Despina (Mozart - Così Fan Tutte); Susanna (Mozart - Le Nozze di Figaro); Marzelline (Beethoven - Fidelio); Adele (J. Strauss - Die Fledermaus).
Famous singers: Kathleen Battle; Barbara Bonney; Ileana Cotrubas; Valerie Masterson; Anneliese Rothenberger; Rita Streich; Lillian Watson.
"Coloratura - When a singer, usually of unnaturally high voice, does more than is strictly necessary." - Peter Gammond, Bluffers Guide to Music.
Famous roles: Queen of the Night (Mozart - The Magic Flute); Constanze (Mozart - Die Entführung aus dem Serail); Lucia (Donizetti - Lucia di Lammermoor); Olympia (Offenbach - The Tales of Hoffman); Semiramide (Rossini - Semiramide).
Famous singers: June Anderson; Maria Callas; Edita Gruberova; Sumi Jo; Nellie Melba; Adelina Patti; Beverly Sills; Dame Joan Sutherland.
Famous roles: Mimì (Puccini - La Bohème); Eva (Wagner: Die Meistersinger von Nürnberg); Tatiana (Tchaikovsky - Eugene Onegin); Liù (Puccini - Turandot).
Famous singers: Licia Albanese; Montserrat Caballé; Mirella Freni; Gundula Janowitz; Kiri Te Kanawa; Victoria de Los Angeles; Elisabeth Schwarzkopf.
Famous roles: Floria Tosca (Puccini - Tosca); Aida (Verdi - Aida); Sieglinde (Wagner - Die Walküre); Elisabeth de Valois (Verdi - Don Carlos); Leonora (Verdi: La Forza del Destino).
Famous singers: Maria Callas; Jessye Norman; Rosalind Plowright; Katia Ricciarelli; Cheryl Studer; Carol Vaness; Julia Varady.
Famous roles: Brünnhilde (Wagner - Der Ring des Nibelungen); Isolde (Wagner: Tristan und Isolde) Elektra (R Strauss - Elektra); Norma (Bellini - Norma); Turandot (Puccini - Turandot).
Famous singers: Jane Eaglen; Anne Evans; Rita Hunter; Dame Gwyneth Jones; Birgit Nilsson; Deborah Polaski; Eva Turner.
Famous roles: Cherubino (Mozart - Le Nozze di Figaro); Octavian (R Strauss - Der Rosenkavalier); Charlotte (Massenet - Werther); Carmen (Bizet - Carmen); Dalila (Saint-Saëns - Samson et Dalila).
Famous singers: Cecilia Bartoli; Marilyn Horne; Frederica von Stade.
Famous roles: Amneris (Verdi - Aida); Eboli (Verdi - Don Carlos); Brangäne (Wagner - Tristan und Isolde); Ortrud (Wagner - Lohengrin); Klytemnestra (R Strauss - Elektra); Cassandre (Berlioz - Les Troyens).
Famous singers: Agnes Baltsa; Fiorenza Cossotto; Eva Randová.
Castrati were male singers whose unbroken voices were preserved through castration. This practice was prevalent in church choirs in Italy - women's voices were not allowed - and the preservation of boys' singing powers into adulthood was advantageous both to the church which had invested in training them, and to their families, as castrati could hold the key to financial security.
Towards the end of the 17th century, most leading male roles in serious opera werebeing assigned to castrati; this led to the emergence of the star castrato, and the best known names - or more correctly, pseudonyms - were Caffarelli, Senesino and Farinelli. One of the last operatic castrati, Vellutti, had parts written for him by Rossini and Meyerbeer.
A recording exists, dating from 1902-3, of the Sistine Chapel castrato, Alessandro Moreschi, but the singer was already an old man and the sound could be described in literal and metaphorical terms as 'unearthly'