Édouard Lalo (1823-1892) is known today for a handful of orchestral works, music infused with ‘exotic’ colours borrowed from Spain, Norway and Russia. But like all French composers of the 19th century, he longed for the kind of success that only a successful opera could bring. He wrote two, with a third unfinished at his death, but although the second and finest of them, Le roi d’Ys (1888), was a substantial hit both at home and abroad, he never achieved the acknowledgment of a coveted staging at the Paris Opéra. A pity, as it fully deserved such an accolade, and even now there is a strong case for modern revivals.

The story is based on one of several Breton legends surrounding the sunken city of Ys, sometimes referred to as the Celtic Atlantis. As the opera opens, a lengthy war between Prince Karnac and the city of Ys is finally drawing to a close. The peace treaty demands that Karnac will marry the King’s daughter, Princess Margared. She is secretly in love with the warrior Mylio, though he is believed to have been killed...