Soak and Duke Special at McGrory's

Young starlet from Derry supports established artist from Belfast as guitar meets piano in a battle of the solo performers

I watch Soak's set at McGrory's in Culdaff through Duke Special's dreadlocks. 

Like the hundred or so other audience members packed into this intriguing little venue – known throughout Donegal as a Mecca for live music, having played host to the likes of singing astronaut Chris Hadfield, amongst others – the more senior member of Northern Ireland's professional musical fraternity is eager to see 18-year-old Bridie Monds-Watson perform in person the songs that are currently aired on a loop every couple of hours on BBC Radio 1.

She does so tonight without any backing band, managing to captivate McGrory's with a gutsy stage presence, vocals that never waver, and a finger-picked guitar playing style that is hypnotic in its simplicity – she rarely strums full open chords, choosing instead to follow the lyrical melody on high strings, or thumb deadened bass strings as a minimalist bedrock, allowing the words to take centre stage. With songs as raw and well constructed as these, however, she needs nothing else.

Soak is truly an upcoming artist. Performing at Other Voices during Derry's year as UK City of Culture in 2013 did her the power of good, and she has subsequently recorded a Live Lounge session at Maida Vale studios, signed with the iconic Rough Trade record label, and been championed and mentored by the likes of Zane Lowe – all before reaching her 18th birthday. To see her performing in a hotel bar with one of Northern Ireland's other big name musical stars on an otherwise very quiet Thursday night is, therefore, unusual, to say the least.

But she is happy to be back on home soil – in fact, she returns to her native Derry most weekends, regardless of her touring commitments – and to be performing in a small venue with lots of character, even if it is disconcertingly hushed throughout her short opening set. 'You're allowed to talk,' Soak quips after a spellbinding version of the song that made her name, 'Sea Creatures', though nobody takes up the baton; this is a respectful crowd.

Soak's lyrics chart her course through adolescence, picking up on her parents' arguments as heard through her bedroom floor, 'weekends and cheap thrills' made memorable by the company of friends and good music, and evenings pondering what love really means, and those sorry individuals who 'throw it around like it's worthless'. 

There has always been a maturity in her songwriting, but now Soak seems to have accepted and embraced the fact that she has become a role model for so many young music fans from around the UK and Ireland, and siphoned that experience into her lyrics. 'Be just like me,' she sings on one of her latest singles – her strongest track so far, and tonight's undoubted highlight – 'Be a nobody.'

Such sentiments are rare in modern pop music, but then Soak is original in many ways. Her stripped back sound, high on reverb when she plays electric rather than acoustic, is similar to 1990s alt rock group Mazzy Star – her vocals echoing those of their similarly ethereal lead singer, Hope Sandoval. Yet Soak has not heard their music, she admits afterwards. 

At a time when guitars have fallen out of fashion, when pop acts produce music that is beat-heavy and lyricists prefer to talk about sex rather than insecurities, Soak performs her music alone, without electronic accompaniment or behind six inches of make up, on her own terms. If she happens to be accosted by Kanye West at a Grammy awards ceremony in the near future, don't be surprised.

How to follow a natural born star? Duke Special decides to go for the 80s approach, performing new song, 'Elephant Graveyard' – the first single from his forthcoming synth-heavy eighth studio album Look Out Machines! – all chunky piano chords pounded out to a Depeche Mode rhythm. 

One day Soak too will seek the Muse from other places to keep things fresh and attract new audiences, so this change in aesthetic from the short white Duke is hardly unexpected. ('I don't want to stand still,' remember?) Yet tonight's audience come alive when he returns to his more melodic earlier work, particularly the big hits from his breakout album, Songs from the Deep Forest, which also gained him a short-lived Radio 1 status.

Like Soak, Duke performs them alone, just vocals and piano, which is perhaps a disappointment for many present who were hoping to hear old and new Duke Special songs performed to their full live band potential. After all, he is known for his theatrical stage show, often featuring Victoriana props, multiple instruments and vaudevillian interaction.

Duke, aka Peter Wilson, has the frontman's charm and back catalogue to keep tonight's audience entertained till lights up, but it was always going to be difficult to maintain interest during a headline set as a solo performer. 

As it happens, 'Freewheel' remains a beautiful song beautifully sung, the classic 'Applejack' gets people singing and clapping as the night wears on, and a duet with Soak makes for an interesting finale, but by then the magic has worn off. Lets hope Duke Special doesn't allow another eight years to lapse before returning to McGrory's, and that next time he performs here he brings his band with him.