If you really want to get into a discussion (or read one) about this, go to vocalist.org. Here is a bit from a discussion of the coloratura repertoire. My teacher is a coloratura soprano (I am a light lyric soprano) I have never performed in an opera.Here is her repertoire. . Sopranos have come to be known for singing the ornamental coloratura style, but it is not limited to sopranos. The AGILITY of the voice, the type of ornamentation added in variations and the style of the music composed are components of the coloratura designation.... read on:
Alice Flynn

BTW, alto means high, and it has been shortened from the word contralto, which means "against high". Alto is just an abbreviated way to say contralto; they are the same range. Some definitions of terms below, fioritura= flowery, sobrette= somewhat of a comedy role, (like Despina), spinto= pushed (more powerful) lirico spinto= powerful voice with an edge to it.

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Quote from vocalist.org
Dear List -

Sobrette is NOT, I repeat NOT LIGHTER than lyric coloratura. It is broader, with less fioritura, and a warmer, meatier middle voice.

Before I correct her LC list, let me remind those of you who have not heard me say this ad nauseum before, that the classification of roles is done by the demand on the singer (what she has to sing with and against as far as instrumentation and the remainder of the cast). Just because one LC has sung a role (especially if its Sutherland) does not mean that role is in the LC fach. It usually means (especially if its Sutherland, again) that particular singer had/has qualities of another fach in their voice that allow them to sing the role SAFELY.

Now, on with the corrections:

Barbarina (soubrette, albeit a young one, a future Susanna)
Frau Fluth (full lyric with fioratura or Dramatic Coloratura)
Elena - Mephistopheles (lirco spinto or dramatic)
Pousette - Manon (lyric mezzo)
Sandman/Dew Fairy -Full Lyric
Anne (Rakes) - (full lyric)
Blanche (Dialogues) - lyric or lyric mezzo
Governess (Screw) - FULL lyric
Lauretta (Schicchi) - light to full lyric
Musetta - full to heavy lyric
Sophie (Rosenkavalier) - soubrette with secure height
Vixen - light lyric
Zerlina - soubrette
Alice Ford (Verdi) - lirico spinto
Donna Elvira - heavy lyric
Donna Anna - Dramatic Coloratura, full lyric with flexibility
Esclarmonde - FULL lyric
Juliette - light to full lyric
Marguerite (Huegenots) - lirico spinto
Medea - dramatic coloratura or DRAMATIC
Norma -drmatic coloratura or DRAMATIC
Poppea - full lyric
Rosalinda -Full lyric or DC
Selika - full lyric or DC
Violetta - any voice past light lyric

If anyone has questions about WHY these are the way they are, I'd be happy to explain. Its most often an issue of instrumentation, length, ensemble size and the practicalities of the theater and casting.

Best Regards -

Ron
ronland@geocities.com