It hardly sounds like the springboard for an album, a film, a book and an app. In the 1780s a young Welsh explorer called John Evans journeyed across the unmapped North American continent in search of a tribe of Welsh-speaking Native Americans. His only source for the tribe’s existence – and linguistic preference – was a legend which claimed that a Welsh prince by the name of Madog ab Owain Gwynedd discovered the New World 300 years before Columbus. It’s no plot spoiler to reveal that Evans did not find the tribe.

“Haven’t we met before?” We hadn’t, but Stellan Skarsgård’s friendly greeting immediately sets the tone for an encounter which is so relaxed that thoughts of the explosive Nils, the quiet man who boils over in In Order of Disappearance, almost evaporate. How did this affable, chatty and thoughtful Swede become a man who kills repeatedly and so gruesomely on screen?

Sarah-Jane Morris is in every sense an original voice. One of Britain’s most distinctive and versatile singers, she has enjoyed commercial success, spending five weeks at number 1 with the Communards’ version of "Don’t Leave Me This Way" in 1986, and selling 100,000 of her self-titled solo album in 1989. She has the distinction of having “Me and Mrs Jones”, which featured on the album, banned by the BBC for suspected lesbianism.

This year the nation has been spirited back to 1914. Every aspect of the First World War has been explored - its causes debated, the horrific conditions on the front revisited. And yet there has been less talk of the psychological impact of trench warfare, which is why Nicholas Wright’s new stage adaptation of Regeneration will greatly add to the sum of the centenary coverage. Pat Barker’s novel was published in 1993 - and filmed in 1997 starring Jonathan Pryce - but more than 20 years on there is still no shrewder or more moving account of shellshock.

Sofie Gråbøl as Danish royalty: it hardly stretches credulity. The face of Nordic noir has been a star in her home country ever since appearing in Bille August's Pelle the Conqueror in 1987, but is solely familiar on these shores as Sarah Lund, the jumpered Copenhagen detective from three unmissable series of The Killing. This autumn the only thing that will be recognisable about Gråbøl will be those big blue eyes as she is spirited back to the late Middle Ages, bewigged, bejewelled and billowing, to play a queen of Scotland.

Sarah Willis's day job is as a member of the horn section of the Berlin Philharmonic. In recent years she has also become a roving ambassador for the instrument and a familiar face presenting and interviewing on the Berlin Phil's Digital Concert Hall. In 2010 she released her first solo recording, of the Brahms trio for horn, violin and piano. That combination of instruments is once more the foundation for her second solo CD. But there all similarities end.

I sit down with Cambodian-born, London-based director Hong Khaou to talk about his experience making his first feature film, Lilting, which showed at Sundance film festival in competition, took home the award for best cinematography in the world cinema category, and opened the 28th BFI London Lesbian & Gay Film Festival to great acclaim.  A cheery mood fills the room, his softly-spoken, intelligent musings inflected with an excitability which is utterly endearing.

Celia Imrie is admired and loved as a comic actress. Her conversation, just as much as her performances, is full of her trademarks: sudden darting looks, alertness, natural timing, changes of register. They will all be in display in her cabaret show Laughing Matters.

You can usually trust the buzz around rehearsals. From Glyndebourne, five weeks into preparation for La traviata, which opens tomorrow, one of the team working on Tom Cairns’ new production declared in an e-mail conversation that newcomer soprano Venera Gimadieva was possibly the most definitive Violetta yet. And when I was havering over whether to interview American tenor Michael Fabiano, not by then having watched a wealth of stupendous videos on his website, the response was “you absolutely must”.

DJ, broadcaster and all-round musical pioneer Gilles Peterson is one of the most influential figures in contemporary music. In a career that has grown from a DIY pirate station to running a succession of record labels, global DJing appearances and his own Worldwide Awards, he’s become famous for his commitment to the most unexpected combinations of new sounds and genres, drawn from restless collaborations worldwide.