When Arturo Toscanini, that most exacting of maestros, spoke the words “the voice of an angel,” he had in mind the matchless Italian soprano Renata Tebaldi. These days, wordsmiths are lavishing the same compliment on the Frenchman Philippe Jaroussky, a countertenor currently on tour with the pianist Jérôme Ducros, stopping next at the Palau de les Arts Reina Sofia, in Valencia. Might Toscanini, who died in 1957, ever have encountered the likes of such a beast? Probably not. It’s true that grown men warbling in the highish ranges principally associated with children and women seem to have been with us since the dawn of time. (Frankie Valli would be a modern avatar.) But the ersatz castrati that conservatories are cultivating today are something genuinely new under the sun.

As of the mid–20th century, there were really only two to reckon with: in the U.K., the soothing Alfred Deller, and in the U.S., the spooky Russell Oberlin. Fastidious and elocutionary to a fault, they appealed to sophisticated tastes perhaps only a few bothered to acquire. By now, resistance has ceased to be an option.

The ersatz castrati that conservatories are cultivating today are something genuinely new under the sun.

With the Baroque revival of the 1970s and 1980s, countertenors began springing up like cyborgs grown from the teeth of dragons, often cast in the roles of Monteverdi’s and Vivaldi’s and Handel’s ancient kings and knights and heroes. Today, the talent pool is bottomless. In timbre, our prominent countertenors range from moonlit silver to molten amber. In temperament, there are dreamy types, weepy types, tigers bristling with fury—more varieties than you could hope to classify.

Jaroussky ranks at or close to the top of just about everyone’s list. His early champions thrilled not only to his angelic qualities but to his virtuosity, which some liked to call “diabolical.” It doesn’t hurt his brand one bit that he has the face and silhouette of a Prada model. Best of all, he keeps growing. His clear, liquescent instrument still sits celestially high (more soprano than mezzo, never mind contralto). It still leaps—when the line needs it to—like wildfire. But the poetry, no less of vocal line than of text, seems to be flowing with a spontaneous, unforced mastery that makes each song new. —Matthew Gurewitsch