To witness Anna Calvi take to the stage and start to perform is to see a metamorphosis as miraculous as a caterpillar turning into a butterfly.
The singer/songwriter seems a fragile, near-weightless figure as she approaches the microphone in front of a hushed audience at Glasgow’s Arches venue.
A roadie comes out to hand her the first of a series of guitars and the slightly embarrassed look leaves her eyes to be replaced by steely determination.
There’s not a word of introduction before she plays a chord and unleashes her voice for the first time.
The awkward beauty vanishes instantly, subsumed by a newly-born rock diva.
‘Suzanne and I’- from Calvi’s self-titled 2012 debut album - explodes across the subterranean room in breathtaking fashion.
From that moment on it’s impossible to tear one’s gaze from the performer, who says no more than a handful of words between songs, a shy “thanks” only appearing after five tracks have been belted out with savage gusto.
Her two albums are equally well represented in a set packed with highlights.
There’s also time for a cover of Bruce Springsteen’s ‘Fire’ and a handful of screaming guitar solos worthy of Tom Morello, before she finishes with a quiet “goodnight” and reverts to her previous modest form.