Thunderous applause greeted Bejun Mehta, the American counter-tenor, when he took his bow after a sensational performance of the title role in Handel's Orlando at Covent Garden.

Written for London in 1732, this great masterpiece only entered the Royal Opera's repertoire three years ago.

Now Francisco Negrin's production has returned in triumph with the doyen Handelian Sir Charles Mackerras - also rapturously cheered - at the helm and the Orchestra of the Age of Enlightenment once again classy visitors in the pit.

To give a gist, the medieval knight Orlando goes insane with love then comes to his noble senses nearly four hours later.

This opera seria, full of musical ingenuity and aural effects which constantly leave you dazzled, has many diversions en route, including an extraordinary mad scene and a magician.

The Baroque theatre of Handel's day would have revelled in a chance to use cloud machines, flying chariots, real flames and fountains.

Here the designer, Anthony Baker, opts for a more gentle, Poussin inspired revolving set, a deft mix of tradition and modernity.

Negrin coaxes intelligent, detailed performances, with Camilla Tilling outstanding as a spirited, frustrated Dorinda.

Rosemary Joshua's elegant Angelica, Anna Bonitatibus's Medoro, and bass baritone Kyle Ketelsen as a golden-toned Zoroastro completed a strong cast.

Mackerras conducted with the joyful energy of a young man and the wisdom and musical perspicacity of the octogenarian he is.

Handel wrote the title role for the famous castrato Senesino, said to be very ugly and usually got up in tight bodice, wide skirt, plumed helmet and high-heeled boots.

Behun Mehta, rather handsome, needed none of these extra aids. Instead he relied on courageous acting and a voice that conveyed every shade of emotion and passion.

The moment at which, in his madness, his voice itself becomes a whirling tormented dervish had the audience gripped.

Suddenly one understood why the vocal acrobats of Handel's day were the high-earning celebrities of their time.

There were a few empty seats at this great feast of sound. Fill them.

• Until 13 March, Box office: 020 7304 4000.