While I'm still learning to disentangle my mezzo from my Meistersinger, I enjoyed a lot of the opera on offer in London this year, especially at English National Opera. Parsifal was perfect and Rameau's Castor and Pollux, while probably a little too Germanic in direction with its dancing amputated legs and unerotic nudity, was wonderfully sung. I especially enjoyed the premiere of Nico Muhly's Two Boys, whose internet-era set design suited its perverse modern "love" story.

A young chap from Elsewhere woos an alderman's daughter: not Dick Whittington in panto London, but Wagner's Walther von Stolzing in an unseasonal Nuremberg. No one is going to mind the solstitial disjunction - celebrating midsummer revels in the dead of winter - when this great saga of art and society is buoyed up by Antonio Pappano's lovingly prepared conducting, a good cast, lusty chorus and colourful costumes.

It is unusual in art for collaborators to be of equal star-wattage. The pairing of Benjamin Britten and WH Auden was one such. Another, much longer-lasting, was Stravinsky and Balanchine, a partnership of equals that endured for nearly half a century. More recently, Antony Gormley has worked with both Akram Khan and Sidi Larbi Cherkaoui, to great effect. Can Turnage, McGregor and Wallinger replicate these? This has been the question.

Who is more likely to be an operatic creature of flesh and blood: Puccini's young diva, unexpectedly caught up in the infernal machine of a lustful tyrant, or Tchaikovsky's teenager impetuously pouring out her soul in a love letter to a man she's just fallen for? Usually, you'd go for Tatyana over Tosca every time. At ENO it's currently the other way round.

Theatregoers may be disappointed to read on and discover I mean Otto Nicolai's Die lustigen Weiber von Windsor, the only 19th-century Shakespeare-based opera in the German language to hold the stage. Which it did, and not just in Germany, until the arrival of Verdi's infinitely superior Falstaff. Is this that rare thing, German comedy in music between Beethoven's Eighth Symphony and Richard Strauss's Till Eulenspiegel that's actually funny? Not really; Wagner's Die Meistersinger stands alone.

What’s not to love about Tchaikovsky’s candid, lyric scenes drawn from Pushkin’s masterly verse novel? ENO’s advance publicity summed it up neatly by promising “lost love, tragedy, regret”. We’ve most of us been there. That does mean that truthfulness to life can count for even more in a performance than good singing. Both burned their way through Dmitri Tcherniakov’s radical Bolshoi rethink, but while there are four fine voices to help Deborah Warner’s surprisingly traditional production along, the truth flickers very faintly here.

Is this the year that G&S became definitively chic again? The slow-burn effect of ENO's "Miller Mikado" and Mike Leigh's Topsy-Turvy now results in numerous fringe benefits. Sasha Regan's all-male Union Theatre regime has delivered its best yet - Iolanthe at Wilton's Music Hall, the most touching and funny show I've seen over the last 11 months - and now Charles Court Opera gives us more witty operetta-in-close-up with a cast of nine backed up by two pianos.

Sometimes the most disturbing images exist only in our imaginations - and so the questions posed in the preface to Bartók’s operatic masterpiece Duke Bluebeard’s Castle become especially pertinent: “Where did this happen - outside or within? Where is the stage - outside or within?” The answers, surely, lie “within”, making the prospect of a “semi-staged” climax to Esa-Pekka Salonen’s Philharmonia Bartók series, Infernal Dance, a potentially troubling one.

Imagine what John Cleese might have done with the tale of a slutty sleepwalker who finds herself staying at a packed provincial guest house? Bellini doesn't even touch on farce, let alone psychological investigation. He instead follows the archetypal bel canto formula: dramatic thinness and vocal display.

The English National Opera were taking quite a gamble with last night's Rameau premiere. The daunting basics? A 250-year-old French opera that hasn't yet been properly adopted by its homeland, let alone by Britain; a mildly autistic mythological plot that eulogises the ordered loyalties of brotherly love over the messy complications of sexual desire; and a director, Barrie Kosky, Intendant at Berlin's Komische Oper, where you're not really allowed to break wind without the help of a dramaturg.