‘Sweet, flexible and extensive, being in compass more than two octaves’ was music historian Charles Burney’s verdict on Venanzio Rauzzini, the castrato for whom Mozart wrote the role of Cecilio in Lucio Silla and the motet Exsultate, jubilate. Rauzzini’s famed range – up to top C – is matched, even eclipsed, by Argentinian countertenor Franco Fagioli, who more than any other falsettist I’ve heard suggests how the star castratos of the 18th century might have sounded.

Fagioli’s lyrical singing, whether in the motet’s slow central aria or Sesto’s solos from La clemenza di Tito, has a luxurious, almost feminine sweetness that remains just the right side of indulgence. Judging by the music Mozart composed for him in Lucio Silla, Rauzzini excelled in the smooth negotiation of wide intervals. Fagioli proves equally accomplished in the vertiginous leaps of Cecilio’s aria of tender farewell ‘Ah se a morir’. If his coloratura in Exsultate’s final ‘Alleluja’ can be aggressively driven, his flamboyant virtuosity is never in doubt. And where countertenors typically come across as merely flustered when they seek to express outrage or anguish, the power of Fagioli’s voice means that he sounds genuinely distraught in Ramiro’s turbulent C minor aria from La finta giardiniera. The expert Basel period orchestra, with little to challenge them in most numbers, are properly fiery accomplices here.

While Fagioli’s singing is often viscerally exciting, his characterisation tends to be generalised. I don’t know of another countertenor with Sesto in his repertoire, and I’d be intrigued to hear him sing it on stage. But turn to Cecilia Bartoli, on the Hogwood recording (L’Oiseau-Lyre, 3/95), or Anne Sofie von Otter, with Gardiner (Archiv, 12/91), and you’ll hear an altogether more intense, specific involvement in Sesto’s appalling dilemmas. Both mezzos deploy a subtler range of colour and nuance, and make far more of the texts. Fagioli is inclined to skate over his words, sometimes distorting vowels in the process. Doubtless ignoring my reservations, the countertenor’s legion fans should find plenty to thrill and delight in his celebration of Mozart’s writing for castrato. They may even forgive Pentatone its niggardly 47 minutes’ playing time.