I don't know who is saying contraltos are rare..... seems like an odd statement, because contraltos are born just like sopranos and tenors and baritones and basses.... it's just the natural vocal range a person is born with. Your range is inborn, not contrived or created. You have what is physically shaped in your throat, just like you have your eye color. Maybe fewer women with contralto voices are seriously going into opera careers. Who made the statement that contraltos are rare?

In the Threads on the Singing Voice there is a link to a page that gives you the range that defines each type of voice. By the way, alto and contralto is the same thing. "Alto" meaning high, and contralto being the woman's voice that sings against the high woman's voice. There are roles in opera for each range of voice and for the quality of the range that relate to how a singer would be cast for a particular character in the story. From an earlier thread on what kind of range a singer has, Kris (King Brilliant) asked about her range. Later, Kris found a voice teacher and began learning singing technique, finding that she really is a mezzo soprano. Maybe she will weigh in on this thread and express how stuyding voice has expanded her folk music abilities and enjoyment. Here is a bit copied and pasted of what I posted on that old thread.

table of ranges, which actually is shortened from what people really sing in that range.
Click here

You have to realize that every voice is an individual voice, and these are only generalities about range. The vocal cords you were born with are going to develop as an adult into the range of your voice, but each person has unique qualities to the sound, and depending on how you learn to use your voice and how your health and daily 'workout' of the voice keeps it in shape, you can sing notes that go above and below these general ranges. Don't interpret that high and low notes the dictionary provides as the definite lowest and highest notes for each type of voice - although I am a soprano, I can sing to the LOWEST note they show for a TENOR! The point is, my vocal cords don't sound their best down that low, even though I can reach the low note. My voice has the best sound in the higher part of my range.

Here are more terms that apply to characteristics of voice.
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 "
------- end of quote from vocalist. org

So, as you see, the ranges of the kind of voice you were born with have names, but so do the characteristics of a voice for portraying types of roles.

Here is more on the history of singing
Click here

Alice