Alasdair Nicolson is packing his car in London and about to head north.

He'll take his time over the journey, stopping off with family in Edinburgh and Inverness before making the ferry crossing over the Pentland Firth to Orkney. The long hours at road and sea should come as welcome downtime: events of the past few months have made Nicolson an extremely busy man.

He's a composer, first and foremost. But as artistic director of two major UK music festivals – tomorrow he launches his second edition of Orkney's St Magnus Festival, and last month he succeeded Joanna MacGregor as head of Bath International Music Festival – he's been spending more time programming other people's music than writing his own.

Just one of those posts would be no small commitment. Bath and St Magnus both have noble histories of artist-led innovation and community engagement: Peter Maxwell Davies founded Orkney's festival in 1977 and has since coerced a major chunk of the islands' population to get involved; MacGregor leaves Bath with a legacy of cutting-edge jazz, folk and multimedia collaboration. To uphold both legacies in a climate of dwindling arts budgets is a serious ask of any director.

Is it humanly possible to manage both jobs? "Everyone's been asking me that – I've been asking myself that-" There's trepidation in Nicolson's laugh. "But I hope the answer is yes. The festivals are a month apart. My schedule will be nuts, but as a freelancer I'm used to that. And while I don't want to shrink away from my actual profession as a composer, I remind myself that the Bachs and Haydns and Mozarts of this world all had to write their music and make the concerts happen, too. In a sense I'm just doing things as they used to be done."

Nicolson points out that one benefit of his balancing act is the potential for joint enterprise between festivals. From co-commissioning new work to sharing programme and tour costs, forging closer working links between arts bodies is a vital post-austerity survival tactic.

His mind is already running well into next year's programmes, but there's the small matter of this year's St Magnus to get through first. The festival kicks off tomorrow night with a staging of Bizet's Carmen in Kirkwall's Auction Mart, where "they've kindly cancelled the weekly cattle market for us! The space is perfect," says Nicolson, "and not just because it suits the toreador scenes. It's a market arena designed for people to sit and inspect cows. It's got great sightlines."

Nicolson says he's fascinated by venues that "may not be on the usual classical radar" -- which, given that Orkney has no purpose-built concert halls, is a handy passion. This year he's installing sound installations at listening booths in airports and ferry terminals, and reopening the cavernous mess hall of Scapa Flow's Ness Battery for a the aptly named It Ain't Half Cold Mum.

There are the iconic St Magnus venues, too: the intimate Stromness Town Hall; the sports gym Pickaquoy Centre, where the RSNO will play two programmes; the tiny Italian Chapel, this year host to an Italian gypsy-jazz duo of clarinettist Gianluigi Trovesi and accordionist Gianni Coscia. And, of course, there's St Magnus Cathedral, whose staggering acoustic welcomes the Trondheim Soloists, Aronowitz Ensemble, soprano Gweneth-Ann Jeffers, Florilegium and the Arakaendar Bolivian Choir.

The festival's main event is Michael Tippett's pacifist oratorio A Child of Our Time in a joint performance by the RSNO and the St Magnus Festival Chorus. "An unauditioned choir that numbers 160-plus and is actually extremely good- I defy any urban scene to produce something this impressive," says Nicolson of the Chorus. "This piece will be a good challenge, and they'll be up to it."

The oratorio is famous for its striking integration of American spirituals, but it was inspired by events closer to home, namely the 1938 assassination of a German diplomat by a Jewish refugee and the Nazi government's retaliatory Kristallnacht. Tippett's score and libretto broaden their lament for oppressed people worldwide, and deliver a profound message of courage and reconciliation.

Timely stuff, says Nicolson. "It got me thinking of the Arab Spring: individuals standing alone in Tunisia and triggering major world events." So he's gone for a broader festival theme of exile and refugees, from the Holocaust survivor in Marc Neikrug's "sprechgesang" music-drama Through Roses through to music by Erich Korngold, an Austrian Jew who fled to Hollywood, and Shostakovich, who packed his bags every night for fear of a KGB knock at his door. "Even Carmen at its premiere was a shocking work about gypsy exile and the plight of abused women – far more challenging than the castanets-and-sangria image we have of it today."

It's impossible to discuss St Magnus without a nod to its presiding father figure, Maxwell Davies. "Max and I chat a lot as friends," says Nicolson. "He mentors the composition course alongside Sally Beamish and myself, and has his work performed at the festival. But nowadays he's a hands-off presence. Back when he was still director and lived on Hoy he'd be running down to the phone box every 10 minutes to make concert arrangements. He no longer does that..."

The nature of the job has changed, too. While Maxwell Davies's life and community was consumed by the festival, Nicolson works part-time from London, commuting to Orkney every six weeks or so – "the miracle, or maybe the curse, of the internet age," he says.

But he knows the festival inside out and from many angles. His first St Magnus commissions came in the late 1980s; he has co-ordinated numerous education projects for the festival since then, and was director of the composers' course for five years before taking up overall artistic directorship. Nicolson may live in London, but he's no stranger to the streets of Kirkwall.

Still, the job has had its share of surprises. "This festival is big in reputation, big in scale, but it's run from a very small office," he explains. "There's one full-time manager, one part-time administrator and me. That's it. Bath has an office staff of five times that!"

"So St Magnus hugely relies on volunteers: house staff, box office, accommodation. After my first year as artistic director I realised quite what a delicate balance that is. It only takes one challenging financial year to rock things. Then there's the travel costs, which for Orkney are vast. It's been a challenging year, I won't deny it. But artists and audiences are so fond of this festival that there's a great deal of goodwill around. It's not a difficult sell; we just need to be a bit more strategic these days." And with that he's off: car packed, long drive and another festival ahead.

Orkney's St Magnus Festival opens tomorrow and runs until June 30.