Isn’t it funny? You wait ages for an opera by an eleven-year-old and then two turn up at once. The world’s feature journalists descended on Vienna at Christmas for a new take on Cinderella by Alma Deutscher. What they heard, for what it’s worth, was a precocious, glittery pastiche of Classical manners. Last night was the real deal. Die Schuldigkeit des Ersten Gebots, by Mozart: "The Obligation to Keep the First Commandment". Not a title to make the heart beat faster, is it?

It's time again for surrealist charades at the nothing-doing mansion. Christopher Alden's Handel is back at ENO, making inconsequentiality seem wondrous. Christian Curnyn's conducting sets the tone, with orchestral playing as light as air, and a new cast – with one singer from the previous set switching roles – conceals its art behind what seems like the easiest and most organic of singing and acting.

Recent British-based productions have taken Wagner's paean to creativity, the reconciliation of tradition and the individual talent, at face value.

After a Royal Opera performance of Birtwistle's The Minotaur, a friend spotted Hans Werner Henze in the foyer and had the temerity to ask that annoying question "What did you think?" "Very competent and extremely well performed," came the reply. Which is the measure of Ryan Wigglesworth's Shakespeare adaptation at ENO.

Opera North’s updated version of Humperdinck’s Hansel and Gretel takes place in what looks like a down-at-heel Leeds housing estate, the titular siblings shown filming the story using simple domestic props and back projections. Quite how the impoverished pair have acquired a high-end video camera isn’t made clear; presumably the assorted boxes of Christmas decorations scattered around Giles Cadel’s spare set fell off the back of the same lorry.

“Who says Mozart is not like Rossini?” remarked Juan Diego Flórez, about a quarter of an hour into his debut recital at Symphony Hall. “There are seven high Cs in this aria.” And with a flicker of notes from the pianist Vincenzo Scalera, he was off into "Vado incontro", from Mitridate by the 14-year old Mozart. He wasn’t joking, either.

Wagner’s Tristan left a huge mark on fin de siècle art, on the symbolist poets, even on their pseudonyms; Debussy himself toyed with a four-act opera on the subject.

Jonas Kaufmann’s legion of admirers could rest content. A well-received Lieder evening last week demonstrated that the world’s hottest tenor property had returned, both to London for a three-concert residency at the Barbican, and indeed to singing after burst blood vessels had forced several months of rest and cancelled concerts.

Adriana Lecouvreur deserves to be better known. The opera has a toe-hold in the repertoire, with occasional appearances, usually as a showcase for the soprano in the title role. Its composer, Francesco Cilea, is known for little else, but the opera demonstrates an impressive melodic gift, an ear for orchestral colour, and a rare ability to pace music in step with a complex and extended narrative.

This was supposed to be a triumphant return – one final encore for the production so good that audiences just couldn’t let it go. Instead, this 13^th revival of Jonathan Miller’s Mafia Rigoletto seems like an apology. The designs are handsome as ever, the concept as neat, but the details of both direction and music are so scrappy and scattered that the show feels more like a basement clear-out than a loving restoration.