GUEST, I agree that "best" should not be tossed about indiscriminately. Rarity, on the other hand, is not necessarily a matter of personal preference. There are voices that are unique—strictly one of a kind. For example:—

Although she is often listed as a mezzo-soprano, Marilyn Horne is a "true contralto." Her voice is extraordinary! Rich and flowing, and amazingly flexible for a low voice. And her type of voice is quite rare.

Opera is not as rigid and ritualized as you seem to think, leeneia. And the contralto often gets the guy. Many of the ingénue parts in Rossini's operas (e.g., Rosina in The Barber of Seville) were written for a low mezzo or contralto, but because of the demanding runs and trills and such, not all that many of the lower female voices are sufficiently flexible to manage it, so the roles are often sung (transposed) by sopranos with light, flexible voices, such as coloraturas. But:—

Marilyn Horne (b. 1934), the greatest coloratura mezzo-soprano of the post-World War II period, has tremendous control over her voice. With an impressive range, power and awesome technical control, her low chest tones and floating high notes wow the audiences. Horne's voice type is extremely flexible and the color of her voice is always mezzo-soprano or even contralto rather than soprano. Her voice's size could also fill the largest opera houses easily. Horne's acting ability is also considerable, especially in comic roles like Rosina in The Barber of Seville.

In Saint-Saëns' opera Samson and Delilah, the role of Delilah is written for contralto. And she gets the guy in a number of ways (of course in the end, he drops the temple on her head, but she does make a pretty effective vamp; that's her job). If you really want to hear a contralto at work, listen to a recording of Marilyn Horne singing Mon cœur s'ouvre à ta voix from Samson and Delilah. Her voice is like spun honey. She could give me a haircut anytime!

Another extraordinary voice that is often listed as mezzo-soprano, but sounds more contralto—and has the flexibility to handle Rossini roles—is Cecilia Bartoli. She can also be one helluva clown when she's on stage and it's appropriate to the role. I can't really think of all that many singers with that particular voice quality. Give these two voices a listen, and see if you don't think they are pretty unusual (i.e., rare).

"Rigid and ritualized?" Not these days.

Alice, I love your posts!

Don Firth