“There's a distinct lack of testosterone in the men,” quipped an audience member to his partner during the interval of Handel’s opera Ottone. It was hard to disagree.

Written in 1723, Ottone was born in the midst of the craze for castrati – men who achieved their sensationally sweet and high pitched singing voices by being castrated in childhood. To 21st century ears, the idea of a German emperor singing like a girl is strange to say the least. The voices of lead countertenor Klint van der Linde and Andrew Radley (Adelbarto) came as a jaw-dropping contrast to the baritone of the mysterious Emireno (Grant Doyle).

This production by the English Touring Opera revives this now little-performed piece, which begins with the attack of a ship carrying Teofane – a Byzantine princess and Ottone’s future bride. While Ottone pursues the pirates, a rival prince, Adelbarto, plots to take over the kingdom, as well as Teofane, aided and abetted by his scheming mother. Meanwhile, Ottone’s sister, Matilda, rejected by Adelbarto, wrestles with her hatred and love for him.

The somewhat incoherent plot involves lots of operatic violence, while poor Teofane ( a wonderfully fragile Louise Kemeney) is permanently on the verge of a nervous breakdown. For me, the storyline was secondary to the beauty of the music and performances, not to mention the thrill of watching a Georgian opera in a Georgian city. A particular highlight was the duet Dear Night sung by Gismonda (Gillian Webster) and Matilda (Rosie Aldridge), while Emireno’s aria to a distraught Teofane that her troubles were now at an end was genuinely moving.

The simple yet stunning set brilliantly evoked the golden splendour of Byzantine architecture and Teofane’s sublime lace-effect golden headdress, twinkling and shimmering in the candlelight, will be hard to forget.

If the rapturous response on Tuesday night is anything to go by, Bath audiences are hungry for early opera. Let’s hope we have more – and soon.