“I am a poor student,” the Duke tells a smitten Gilda, in music that can barely keep a straight face, so plush is its melody, so oozing with confidence and privilege.

It’s a short step from there to Cecilia Stinton’s new Rigoletto for Opera Holland Park, which takes him – almost – at his word, transplanting Verdi’s rapey young aristo from 16^th-century Mantua to an Oxford college between the wars: a Bullingdon Club hooray to Rigoletto’s downtrodden college porter with a chest full of medals and a gammy leg.

Innovation is always a risky business. Opera North’s vision and ambition for this production is to create, in effect, a new genre: a combination of staged choral-orchestral performance with contemporary dance.

Partnership and diversity are the buzz words – good ones, too – and the concept brings together the opera company’s soloists, chorus and orchestra with dancers from both Leeds-based Phoenix Dance Theatre and South Africa’s Jazzart Dance Theatre, plus some help from Capetown Opera.

Götterdämmerung is not only the grandest of Wagner’s Ring operas, it is also the most varied. Siegfried’s journey down the Rhine transports him in a short quarter-hour from the hieratic world of the Norns and the World Ash to the soap-opera of the Gibichungs and their anxieties about marriage and political standing (opinion polls?).

Sometimes a production which isn’t trying to do anything too clever can be quite refreshing. Sinéad O’Neill's revival of Annabel Arden’s 2007 Glyndebourne touring production of Donizetti’s L’elisir d’amore is just that.

If you’re going to be locked in an auditorium with a crazed soldier for over 90 minutes, you need to be overwhelmed by the human frailty and baseness in Büchner’s still-shocking stage play of the late 1830s, the spiderweb beauty of Berg’s 1925 score to match it and a vision in various stage pictures. Director Deborah Warner, conductor Antonio Pappano and set designer Hyemi Shin deliver on all fronts.

Why stage Don Giovanni in a post #MeToo world? That’s the question most frequently being asked about Mariame Clément’s new production for Glyndebourne and on its opening night she delivered a response that was as conceptually subtle as it was visually flamboyant.

The Pearl Fishers is very much a mid-19^th century Romantic opera, with a plot that’s basically a love triangle set in an exotic location. Its writers, Michel Carré and Eugène Cormon, were not the greatest of plot inventors, and after hearing the opening scene alone, you might think much the same about the inspiration of the music, beautifully crafted though it is.

Two recent operas by women have opened in London’s two main houses within a week. Both have superbly crafted librettos dealing with gun violence without a shot being fired, giddyingly fine production values and true ensembles guided by perfect conducting. The main difference is that while Kaija Saariaho’s Innocence feels to me ice-cold musically, and not always coherent with dramatic or vocal possibilities, Jeanine Tesori’s Blue hits us in the guts when it matters most.

Invasion by a colonising power has convulsed a country, dividing families – even individuals – between the rival claims of resistance and collaboration. A captured freedom-fighter from the indigenous elite faces execution; an imperial general hopes to wed his widow and bring a kind of peace to the conquered land.

To create a sensitive and original music-drama around the subject of a school killing is a colossal achievement. Director Simon Stone, set designer Chloe Lamford and novelist Sofi Oksanen’s cutting libretto make Innocence seem like a masterpiece. I wish I were less ambivalent about Kaija Saariaho’s score.