Kathryn Williams, St Pancras Old Church, London

Inside the tiny, picture-postcard St Pancras Old Church – reputedly one of the oldest in England – there is no respite from the heat. It may be the hottest August day for a decade, but the 100 or more souls in attendance are sticking (literally) to their seats, entranced by the music wafting up to the rafters.

“I think I’m more suited to a Russian climate,” says Kathryn Williams, taking off her black cardigan to a few ironic whoops. She follows this with a frank assessment of under-arm hygiene in hot weather, before the acoustic trio (she is flanked by a guitarist and cellist) eases into another deliciously bitter-sweet number from Crown Electric, Williams’ forthcoming new album.

She gives the crowd a frank assessment of under-arm hygiene in hot weather

There was a time – at the start of her career, Mercury nominations and all that – when Kathryn Williams struggled with stage fright, trying to establish the confidence that her talent deserved. But that was then – these days, the confidence is clear to see, not only in the bawdy banter, but in some of her finest song-writing to date.

Williams has always excelled at her craft, but the material on Crown Electric – much of which gets aired in this tour-opening show – reveals an artist stepping up a level, her unique brand of soulful folk given a new, broader set of wings.

The catchy, sometimes poppy melodies are still present, as are the occasional folktronica grooves, and lyrics that effortlessly place domestic detail next to poignant and heartfelt honesty. “I never lost love, I gave it away” is the stinging admission in Gave it Away, whilst the particular pains of the start of the week get mused upon in Monday Morning.

The new record sees Williams collaborate with Ed Harcourt on a few tracks, and lo and behold, the wandering troubadour is lurking at the back of the church, until called up to add some piano to the song, Sequins. It’s a show highlight, Kathryn ditching the guitar to let her vocals soar across an unashamedly-sounding old-school ballad, its skewed rhetoric about “finally feeling numb” reminiscent of classic Tom Waits.

“It feels fantastic playing these songs,” our gal declares at the end of the night, before thanking the audience, her band, her husband (“for impregnating me”), and her manager, whom she dedicates the last number to, a cover of Bruce Springsteen’s Dancing in the Dark. Slowed down and dressed with pitch-perfect harmonising, it’s a more than fitting finale to a great gig. Undoubtedly, the Boss would have approved.

Kathryn Williams tours the UK later this year