There’s something inherently theatrical about the countertenor voice. Suspended between registers, it hangs like a high-wire act of human anatomy, sounding at once ancient and radically modern. In Countertenor, master practitioner Anthony Roth Costanzo peels back the layers of this vocal art form with candour, curiosity and even comedy.

Costanzo is a Grammy-winning American countertenor, author, producer and arts leader, who began performing professionally as a child. After early work in musical theatre, film and opera, he trained at Princeton University and the Manhattan School of Music, overcoming thyroid cancer during his studies without losing his singing voice. His international opera career accelerated after winning the Metropolitan Opera National Council Auditions in 2009, and he became especially known for his acclaimed portrayal of the title role in Phelim McDermott’s production of the Philip Glass opera Akhnaten.

Costanzo sets the home key of his book early, with a memorable recounting of the opening night of Akhnaten at London’s English National Opera. Required to enter the stage entirely nude as the titular pharaoh, Costanzo details the gruelling preparation – from electrical-stimulation workouts sourced via Grindr to an unsparing ‘full Hollywood’ body wax – with buoyant, self-deprecating humour. Yet beneath...