Some famous female roles in the history of opera have only possible because 19th-century composers started giving important roles to:

Mezzo-sopranosa  mezzo-soprano  or  mezzo  is a  type  of  classical  female  singing  voice. the  vocal range of mezzo-sopranos  is between the  soprano  and the  contralto  voice types., which usually goes from the a below  middle c  to the a two octaves above. in the lower and upper extremes, some mezzo-sopranos can reach down to the f below middle c and as high as "high c". this type of voice is generally divided into the coloratura, lyric, and dramatic mezzo-soprano.