Tosca, St Columb's Cathedral, Londonderry - Piccard in Space, Queen Elizabeth Hall, London

Two dramas coursed through NI Opera's triumphant debut production in Londonderry.

The first was that of Tosca, updated to the 1970s by director Oliver Mears in a three-venue, site-specific staging. The second was that of a city opening Protestant and Roman Catholic buildings to audiences and performers from both communities in a week in which rehearsals and performances were disrupted by real and hoax bombs in the city. History is not a faraway thing in Derry. It's weighty, complex and contentious. Yet for three days, St Columb's Anglican Cathedral became Sant'Andrea della Valle, complete with monstrance, madonna and incense.

Though Mears stopped short of drawing crude parallels between Napoleonic Rome and 1970s Northern Ireland, his Tosca emphasised the dreadful helplessness of two apolitical people caught in a violent political conflict. Floria Tosca (Giselle Allen) and Mario Cavaradossi (Jesús León) are not fighters. One is a singer: a local celebrity who is happy to perform for the corrupt police chief, Scarpia (Paul Carey Jones), even flirt with him. The other is a painter. Only when Angelotti (John Molloy) takes refuge in the church where Cavaradossi is working does the political become personal. In a place where most people know someone who was involved in the Troubles – a cousin, a neighbour, a schoolfriend – their dilemma has particular resonance. And as Puccini's scandalous, sulphurous Te Deum seamlessly folded into Ian Mills's magnificent organ improvisation, we were all part of the Sant'Andrea congregation.

Having hooked his audience in Act I, Mears progressively narrowed the focus in Acts II and III. A short stroll under skies like a new bruise took us to Derry's Guildhall, the heavy oak panels of Scarpia's office, a boil-in-the-bag dinner and a filing cabinet full of arrest papers. With the orchestra to one side, the balance under conductor Nicholas Chalmers was near-ideal, the ornate off-stage cantata clear, the instrumental solos sinuous and predatory. Obsessively cleaning his spectacles, Carey-Jones's slight Scarpia grew in stature as he detailed his manifesto of rape and sexual assault, while Allen navigated Tosca's trajectory from contemptuous diva to lost child to murderess, her sound and phrasing compelling and idiomatic. This was no swift stab but a slow, sweaty mutilation.

In the derelict splendour of St Columb's Hall, the curtains opened on to a tiled execution room. As James Elliott's "Shepherd's Song" fluted through the air, an anonymous prisoner was killed and dragged away. León's aria had sepia poignancy in this squalid abattoir, the floor and walls wet from a cursory hosing down of another man's blood. The standing ovation was a given, and fully deserved by all involved, from the three principals to Molloy's desperate Angelotti, Scarpia's henchmen, the young local chorus, the orchestra, the smallest choirboy. After decades of hosting touring productions, Derry had its own opera, cast to compete with Leeds, Cardiff and Glasgow, and developed with a new company that is adamantly regional in focus. A tour of Orpheus in the Underworld follows this autumn, then Hansel and Gretel in Belfast. I'll be there. Will you?

Heart on sleeve, head in the clouds, Will Gregory's first opera Piccard in Space plays like a work for children. There are milk-white skeins of melody for flute and violin that seem to have crept in from Peter Grimes, maudlin waltzes, strutting foxtrots, accompanied recitatives, even a fugue. What there are surprisingly few of, given Gregory's fame as the less photogenic half of Goldfrapp, is synthesisers, though a bank of six augmented the BBC Concert Orchestra in Jude Kelly's semi-staging at the Queen Elizabeth Hall.

Based on Auguste Piccard's perilous 1930 journey to the stratosphere in a cramped aluminium globe suspended from a hot-air balloon, Piccard in Space is an interactive history lesson with a nostalgic dash of sci-fi electronica at the zenith of Piccard's flight. Like the hero and his assistant Paul Kipfer (Robin Tritschler), Gregory's music goes up, then goes down. Much of it sounds like a game of consequences between the young Vaughan Williams and Giorgio Moroder. I still don't understand relativity, even after the singalong led by Andrew Shore's Piccard. Nor do I buy Isaac Newton (Nicholas Clapton) as a camply malevolent Ghost of Physics Past and Albert Einstein (Leigh Melrose) as a hip-grinding, finger-clicking sex-god. But for science-loving 10 year-olds, it's harmless, wholesome fun.

'Piccard in Space', BBC Radio 3 (13 Apr)

Next Week:

Anna Picard sees Paul Curran drag Rimsky Korsakov's The Tsar's Bride into the 21st century

Classical Choice

Vasily Petrenko conducts cellist Alban Gerhardt and the Royal Liverpool Philharmonic for Strauss's Don Quixote, Liszt's Mephisto Waltz and Beethoven's Seventh Symphony, Philharmonic Hall, Liverpool (Tue). Tim Albery's Opera North production of Fidelio opens at the Grand Theatre, Leeds, with Emma Bell as Leonore (from Thu).