51�Թ�

But it happened to include a performance by a noted traditional mezzo-soprano, Jamie Barton, that already sets a high standard for operatic performance of the young year.

Three countertenors have been cast, including as Julius Caesar, a vocally demanding role often given to a mezzo-soprano.

The song builds and builds with an electric guitar that matches the singer's mezzo-soprano and four-octave vocals that merge into the heavy country production backed by drums and banjos.

The mezzo-soprano Mildred Miller Posvar sang opera’s so-called trouser roles so many times that one of her daughters once told a friend, “My mommy is a boy.”

Rachvelishvili, the Georgian mezzo-soprano, had spent the previous decade crisscrossing the world, blazing through some of the most difficult parts in opera.