For most singers, walking onto a stage with no clue as to what you're about to sing would be the stuff of nightmares. But for Lauren Kinsella, it`s the whole point. The Dubliner is one of a small vanguard of vocalists pushing the "jazz singer" envelope to its limits, challenging the old stereotype of the vocalist as the one who sings the written tune and then steps back and lets the "musicians" improvise.

For Kinsella (33), the voice is an instrument, capable of the same range of expression and improvisational dexterity as any other instrument.

“I’ve always been drawn to that,” she says, “being part of the ensemble, being inside the sound. When I’m soundchecking, I always say to the sound engineer that it’s not really ‘voice plus ensemble’. We’re working together musically as a unit.”

Kinsella's climb to the upper branches of the UK jazz tree has been swift. Since she moved to London in 2010, she has been attracting acclaim from the critics and generous praise from her fellow musicians, and she has a shelf-full of awards to prove it, including the Kenny Wheeler Jazz Prize from the Royal Academy and the Jazzlines Fellowship. Earlier this year, she was named Vocalist of the Year by London's Jazz FM.

What has set the Sandymount native apart is the way she interacts with her fellow musicians and the fearless way she uses her voice. Sure, she sings words – she grew up in a house full of books, and many of her compositions use poetry as source material – but she also deploys a range of non-verbal sounds, from pure-toned vowels to a menagerie of shrieks, yelps, clicks and puffs of air. To audiences more accustomed to singers sticking to their lines, it can be an alarming experience.

“For me it’s all about sound,” she explains. “I’m thinking about resonance, about placement of notes, what I can do inside my mouth, or shape words in terms of the tongue and lips.

“Because it’s play!” she adds, laughing. “I think when improvisers talk about ‘playing’, it’s actually like a child plays, using their imagination, having fun, doing something that they feel freedom within. I certainly feel that.”

Ballet classes

She dates her affinity with improvisation to ballet classes in childhood; her favourite part was always the bit at the end when students had to invent their own dance. But at first, her vocal talents drew her more towards the musical certainties and technical precision of classical performance, and she credits her early teachers and mentors with giving her a firm grounding in vocal technique.

“In secondary school, I sang a lot of music and that’s where I learned about the fundamentals of my instrument. I had some wonderful and encouraging teachers – Evelyn Hearns, Sheila McCarthy, Máiréad Ní Chondúin – I owe a lot to these people for their support, knowledge and commitment to music. I sang a lot of classical music like Rutter, Haydn, Handel, Britten – beautiful and demanding vocal music. But I also sang folk music from Eastern Europe and Scandinavia, Spanish madrigals – a mixed bag, really.”

But the day she bought a copy of Swingin' Easy, the classic 1957 recording by Sarah Vaughan, a light went on in her head. "That album was a bit of a game-changer. I'd never really heard somebody improvise vocally like that, where they were singing through harmonic progressions with such ease. Her harmonic and rhythmic mastery, her vocal control in timbre, projection, dynamics and swing feel – it blew my mind."

And so, at 23, she went to Newpark Music Centre in Blackrock to study jazz with bassist and composer Ronan Guilfoyle. Exposure to the technical demands of contemporary jazz presented new challenges which she embraced with gusto. Studying alongside instrumental musicians, who were pushing the limits of technique, presented her with a new horizon. Further studies in Switzerland, Scandinavia, and Bangalore, India, with South Indian Karnatic singer RA Ramamani, culiminated in an MA at the Royal Academy in London.

Ambient folk

There she forged the musical relationships that are central to her many and diverse projects today: the Lauren Kinsella Ensemble for her own compositions; Snowpoet, an ambient folk sextet she co-leads with multi-instrumentalist Chris Hyson; the pan-European Abhra project with saxophonist Julien Pontvianne; as well as regular calls from some of her most adventurous peers on the London scene.

Kinsella is home this month to improvise in three different settings: performing her own compositions with a new quintet at Galway Jazz Festival; presenting a Monster Music Improv for children around the country; and treading the boards for composer Ian Wilson's experimental opera, The Last Siren, at the Dublin Theatre Festival.

The opera project gave her an opportunity to rekindle her love of improvisation in movement. It’s a demanding role for a singer, combining text, movement and vocal improv, more opera or performance art than jazz. And it’s the sort of highwire act that would have lesser singers quivering in the wings.

“Yeh, it is scary,” she admits. “It’s really challenging, people aren’t just sitting in the audience listening to my sound. They’re watching my movements, how I develop sound through movement, and how I connect the text.”

She laughs remembering the audience when they toured the project in the UK last year. “People would come up afterwards and say, ‘Oh, it must have taken you months to learn all that music! How did you learn it all? And I would say to them, [shouts] ‘THE MUSIC IS IMPROVISED!’ Yes, it did take me a while to learn the text, but once the text is in your head, then it’s up to you to create a story, to create a narrative, to create new melodies or motifs, or progressions, or resolutions.”

Nerves of steel

Though she clearly has nerves of steel, she admits there are times her courage falters. “If I have a big gig coming up, sometimes I call my Dad in Dublin, and I’ll be like, ‘Oh God, this is really important, and it has to go really well, and I have to nail it,’ and he goes, ‘Love, you ring me every time, and you always say the same thing. You’ll be fine. You are at your best under pressure.’ And I think he’s right,” she adds thoughtfully. “I definitely engage with challenging music because, yeh, it triggers something in me.”

“But the music on the page is only a starting-point, it’s a point of departure, and when you work with different musicians, they can open up new worlds for you, and you go there with them and you engage in that musical dialogue, and it’s just so exciting, because it’s fresh. The more you trust each other, the more you become familiar with the material, the more freedom you have from the material. For me, that’s what improvisation is all about. And  the music on the page is only a starting-point,”

Catch the voice – Lauren Kinsella in performance

Galway Jazz Festival (October 6-9)

Kinsella performs music commissioned by the Marsden Jazz Festival last year, as part of the PRS's Women Make Music award, with her London quintet. The revamped festival, under artistic director Matthew Berrill, also features UK saxophonist Andy Sheppard, Norwegian pianist Christian Wallumrød, Japanese pianist Izumi Kimura, and high-quality Irish jazz. gjf16.com/lauren-kinsella.html

The Last Siren (October 15, Project Arts Centre, Dublin)

Described by composer Ian Wilson as "an experimental, semi-improvised monodrama", The Last Siren, directed by Ksenija Krnajski, matches Kinsella with sound art collective The Quiet Club. Part of the Dublin Theatre Festival. dublintheatrefestival.com

Monster Music Improv (nationwide tour, October 21-31):

An innovative project to introduce children to the joy of improvisation, blending music and visuals, featuring Kinsella, Dublin guitarist and electronics guru Shane Latimer, and live cartoonist Patrick Sanders. Limerick, Drogheda, Navan, Roscommon, Ennis, Dublin, Lisburn, Wexford and Newbridge. improvisedmusic.ie/events/details/monster-music-improv-2016-tour