Aman who doesn’t play many concerts – this is his first solo live performance in seven years – Brian Eno certainly knows how to pick his venues. It’s hard to imagine a gig ever took place in more ornate surroundings than that of Venice’s most celebrated opera house, a veritable symphony of gilt and stucco. It’s lent a slightly surreal edge by tonight’s audience. That’s partly because some of them appear to have dressed for the opera, and others for a gig – gents in black tie and their companions in sequined evening gowns sit next to gnarled, pony-tail sporting rock’n’roll survivors in battered leather – but mostly because, looking round the auditorium, it’s hard not to notice that a significant proportion of Brian Eno’s Venetian fanbase seems to be made up of men who look not unlike Brian Eno. Initially at least, you wonder if Brian Eno is among them: he’s certainly not on the stage as his 2016 composition The Ship gently begins. Instead, it’s filled with members of the Baltic Sea Philharmonic Orchestra, playing their instruments while slowly walking around amid gusts of dry ice, like a more populous and sedate take on David Byrne’s acclaimed American Utopia live shows. Their conductor Kristjan Järvi is similarly unbound, often directing the musicians by running up to them. On occasions, he turns to face the audience, making him seem less like a conductor, but a man engaged in rapturous interpretative dance: later in the show, keeping time with a shaker in each hand, he looks not unlike a highbrow version of the Happy Mondays’ Bez. As the sound of the orchestra builds, Eno slips quietly into their midst and begins singing in a surprisingly deep voice, augmented by an electronic harmoniser. The Ship is a curious piece, effectively an attempt to marry the two polarities of Eno’s oeuvre – songs and drifting ambient works – it was simultaneously impressive and quite hard work on record: the kind of thing you admire rather than love. If you overlook the essential contradiction at the centre of performing Eno’s brand of ambient music in a theatre – he once said it should be “as ignorable as it is interesting”, but it’s difficult to ignore if it’s being played directly in front of you at a thunderous volume – the orchestration adds an impressive degree of drama, amplifying the swells and surges of what’s essentially a 20 minute drone, augmented with creaking sound effects and a female voice that’s largely incomprehensible. Eno’s vocals, meanwhile, feel oddly folky, not an adjective often applied to his music, but both the melody and its repetitiousness have something of the traditional ballad about them. It says something about the The Ship’s gloom-laden mien that Fickle Sun seems lighter: with its lapses into something close to silence and racked vocal, it bears resemblance to Scott Walker’s later work and comes complete with an apparently heartfelt but algorithm-generated narration about war by comic actor Peter Serafinowicz, who unexpectedly doubles up on backing vocals (he can, Eno avers from the stage, “sing a low C, easily”). A cover of The Velvet Underground’s I’m Set Free closed The Ship album, to the confusion of a lot of critics, who, despite Eno’s lengthy explication, struggled to see its connection to what came before: what was a song that so obviously adhered to a standard structure doing amid all this material that aimed to do away with “the normal underpinnings of rhythmic structure and chord progression”? The orchestrated version, however, is so beautiful as to sweep away any criticism. You’re just delighted to listen to it, even if its loveliness does seem to undermine The Ship’s central hypothesis, as strong an argument for retaining the normal underpinnings of a song as you could wish for. The handful of songs that close the gig mostly stick to Eno’s 21st-century catalogue – And Then So Clear from 2005’s Another Day on Earth, three tracks from last years eco-disaster-themed ForeverAndEverNoMore. But 1977’s By This River is the highlight. Blessed with one of the sweetest melodies its author ever composed: with harp replacing piano as its chief instrument, the orchestral take effects a subtle transformation, trading in the original’s summer night drowsiness for an autumnal glow. By his own admission, he’s only playing because performing with an orchestra was “part of the deal” of winning Venice’s Gold Lion award for music, although the show has been extended into a brief tour. And, it has to be said, amid the Baltic Sea Philharmonic musicians, Eno doesn’t look much like a man who’s been strong-armed against his will. As dinner suits, grizzled rock’n’roll survivors and Brian Eno lookalikes rise as one in a standing ovation that requires Kristjan Järvi’s conducting skills to quiet down, he looks rather delighted.