Productions of The Marriage of Figaro tend to press their thumbs on the comic or tragic side of the scales that hover so evenly throughout Mozart’s inexhaustible work. Director Martin Lloyd-Evans mostly favoured a darker interpretation at The Grange Festival, despite long stretches of niftily managed funny business.

Singer Ian Bostridge once described The Diary of One who Disappeared as “a song cycle gone wrong”. But this reimagining of it as an opera, by the Belgian director Ivo van Hove at the Royal Opera’s Linbury Theatre, also goes wrong, throwing in various extras which detract from rather than enhance the piece’s impact. I am no stranger to being baffled in an opera house.

The whole raison d’être of the Longborough Festival was always the performance of its founder Martin Graham’s beloved Wagner.

"Waiting is always wearisome," declare the socialites as glitter-and-be-gay Manon Lescaut receives in the home of her nasty old "protector" Geronte. Despite the numerous sugar-plums Puccini weaves into his first fluent operatic masterpiece, waiting is very wearisome in the first half of Karolina Sofulak's new production for Opera Holland Park.

It is a coincidence - and probably no more than that - that Garsington Opera has opened its 30th birthday season with the “founding work of modern Czech opera” in the year that also marks the 30th anniversary of the Velvet Revolution in Prague.

All happy 18th century couples are alike, it seems, and that makes for a certain placidity in Gluck's pastoral Bauci e Filomene for the (unhappy) wedding of Ferdinand, Duke of Parma and Maria Amalia, Archduchess of Austria. All unhappy couples are unhappy in different ways, especially if the marital misunderstanding takes place when you're bringing your wife back from the land of the dead.

Flirtations and fragile alliances, lies, betrayals, schemes and the ever-present promise of sex – Love Island may be back on our screens next week, but it has nothing on Handel's Agrippina. Imperial Rome is the backdrop for one of the composer’s most deliciously cynical comedies, where love is an afterthought and power is the only game in town.

What happens on the stage of Stockhausen’s first opera would fill a book – quite a bad novel – but the plot is simple enough. Michael grows up with a domineering, game-hunting father and mentally unstable mother; discovers sex; passes his exams; travels the globe and finds his calling in life as a visionary and saviour.

Stockhausen stands alongside Monteverdi and Beethoven as a composer who exploded the understanding of his art. Stockhausen deeply changed the relationship between space, time and music; there’s a human, intimate dimension to his composition, and he predicted the future.

Mid-career, moving ever further away from composing for concert platform and church towards the stage, Berlioz found himself unsure where his take on Faust belonged. In the end he hedged his bets and titled it a "dramatic legend". Staging it as an opera, as he really wanted, requires the work of a theatrical plastic surgeon.