It's not over until the plastic surgeon sings

It used to be the case that a night at the opera entailed predictably high-voltage romantic melodrama on stage, with plots filled with unrequited love, murderous passions and a fat lady's swansong.

Now, the modern face of opera, it appears, is dealing with themes that are more "kitchen sink realism" than the classical topics usually regurgitated for traditional audiences.

Operas have dealt with such gritty themes as pregnancy, murders arranged on the internet and plastic surgery, and one performance featured simulated oral sex on the stage of the Royal Opera House.

Most recently, The Opera Group has collaborated closely with the Institute of Psychiatry to create a show dedicated to dementia, with a lead character called Mr D, who is suffering from memory loss and psychological agitation. The Lion's Face, whose libretto is written by the poet Glyn Maxwell, is set to be performed at the Brighton Festival on 20 May, and then in London at the Royal Opera House's Linbury Studio Theatre.

Its sensitive subject matter is indicative of the way opera is being more creative about subject matter in a bid to attract younger audiences, which experts have warned the industry desperately needs.

Mr Maxwell said he welcomed such an unconventional topic: "It's like no other project I've done in theatre... but I have tried to make it a human story with plausible characters and some humour to leaven its darker aspects.

"It does have a man with dementia in it, but there are plenty of characters – even in Shakespeare – who are beyond coherence; look at Ophelia from Hamlet, or Lady Macbeth."

The idea emerged from a workshop in which the composer Elena Langer was exploring wordlessness. The team of opera singers and producers joined experts at the South London and Maudsley NHS Foundation Trust and King's College to develop their understanding of the characters. Mr Maxwell met carers, three Alzheimer's patients – some of whom were experiencing early symptoms – and a host of medical professionals including nurses and research scientists.

Mr Maxwell spent two years researching the illness before writing the libretto, which begins with a seemingly trivial incident when an elderly man forgets his way home and eventually leads to his mental unravelling and retreat into an inner world.

"It is shaped like a detective story in which you want to know what's agitating the old man. He has a very bad reaction to something, obviously a memory from so long ago that it pre-dates his wife. It's a romantic memory. She has to cope with that," said Mr Maxwell.

Next season, The Royal Opera will be presenting the world premiere of Anna Nicole, an opera by Mark-Anthony Turnage based on the tumultuous life of the American glamour model and actress Anna Nicole Smith, who died in 2007, aged 39, after an apparent drug overdose.

It has also created a strand called Opera Shots in which mini-productions will be developed, including Jocelyn Pook's opera Ingerland, about football mania, and Nitin Sawhney's Entanglement, which focuses on a woman taking a pregnancy test.

English National Opera has also transformed its programme. Later this year, it will stage the UK premiere of A Dog's Heart, based on Bulgakov's satiric novel Heart of a Dog, featuring Sharik, a stray dog who becomes a human after a Frankenstein-like organ transplant by his master.

Another premiere, Two Boys, is based on true events in which a teenager attempts to arrange his own murder through the internet. It is a co-production with the Metropolitan Opera and will be staged on 24 June 2011.

The new face of opera

*Powder her Face by Thomas Adès, which comes to the end of its run in the Linbury Studio Theatre at the Royal Opera House on 12 May, is based on the life of Margaret, Duchess of Argyll, whose sexual exploits were the stuff of scandal and gossip in Britain in 1963. It features simulated oral sex on stage.

*Satyagraha, the successful Philip Glass opera which had sell out performances at English National Opera's Coliseum earlier this year, tells of the early life of Mahatma Gandhi and his development of non-violent protests.

*The UK premiere of Parthenogenesis by James MacMillan was staged in June 2009, based on the story of a woman shocked during a wartime bomb into conceiving a child.

*Skin Deep revolved around the theme of plastic surgery and was composed by David Sawer with a libretto by the comedy writer Armando Iannucci. It was commissioned by Opera North and set in the clinic of the cosmetic surgery genius, Doktor Needlemeier, whose slogan is "Putting right what nature got wrong'.

*Tête à Tête opera company's Push! was billed as a unique celebration of giving birth. Composed by David Bruce with a libretto by Anna Reynolds, it gained popular and critical acclaim in 2007 at the Riverside Studios in London.

*The Shops, a comic opera about shopping and stealing by Edward Rushton, was produced by The Opera Group and performed in the Linbury Studio Theatre in September 2007.