Russell Oberlin, one of the 20th century’s most celebrated countertenors, whose voice was famed for an earthy robustness that belied the ethereal heights to which it could ascend, died on Friday in Manhattan. He was 88.

His assistant, Zachary Stains, confirmed the death.

Ideally possessed of a haunting, otherworldly beauty, the voice of a countertenor is comparable in range to that of an alto. Today, countertenors, among them David Daniels, Drew Minter and Derek Lee Ragin, are legion on opera stages, in recital halls and on recordings.

But in the mid-20th century, there were just two of international repute: the English countertenor Alfred Deller and Mr. Oberlin. Both men were credited with helping spur the modern renaissance of the countertenor and the corresponding early-music revival of the postwar years — with Mr. Oberlin, an Ohio native, at the center of the movement in the United States.

Critics lauded Mr. Oberlin for his sensitive phrasing, crystalline diction and full, warm, vibrato-rich tone that was devoid of the brittleness and hootiness that for countertenors are looming occupational hazards.