Rachel Zeffira, St Andrews, Holborn, London

Rachel Zeffira performs her first headline gig at St Andrew Holborn on October 18, 2012 in London, United Kingdom (Getty Images)

There could be no more arresting an opening to a gig. As the audience faced the orchestra, awaiting the arrival of the Canadian soprano and multi-instrumentalist composer Rachel Zeffira, a beautiful sound erupted from behind, sending heads turning in the opposite direction.

Recognisable by her tumbling mane of dark brown hair, Zeffira herself sat high in the balcony at the church organ, flanked by two percussionists and a six-piece female choir adding ghostly vocals to her imposing opening song “Here On In”. As Zeffira and her choir made their way to the stage, a string quartet and double bass took over.

It set the tone for a breathtaking show, one that felt nothing like a first solo performance. Zeffira has already proven herself as one half of Cat’s Eyes, the project she launched alongside The Horrors’ front man Faris Badwan (who is sat in the pews tonight) with a stunning debut album last year whose leftfield gauzy orchestral pop sounded unlike anything else at the time. This was the first opportunity to showcase her self-produced debut solo album, The Deserters, out in December.

On the grand piano the classically trained soprano led arrangements that draw influence from the emotional, melodic power of cinematic composer Ennio Morricone, while wrapping them into perfectly packaged baroque-pop songs. On “Star”, mournful strings combined with oboe and clarinet, as Zeffira’s soprano voice and the choir soared in harmony, filling the church. It was a moment of unutterable beauty. In acknowledgement of just how well it worked, given even more powerful dimensions by the ideal acoustics, she smiled warmly at her choir and her smiles were returned.

The centre-piece was just as mesmerising. “Silver City Days” she performed alone at the piano, her fingers gracefully running over the keys, like a waterfall, her gentle lilting voice adding to the hypnotic dream-like quality. Zeffira’s solo material shares much with that of Cat’s Eyes, whose “Love You Anyway” she performed without Badwan. It has the same haunting and hazy feel, a little darkness within the beautiful orchestrations, and soothing vocals that, even in the more percussion-driven “Break the Spell”, retain fragility.

Zeffira might have been the least known member of Cat’s Eyes, but surely that won’t be for much longer.