What’s in a name? Well, when you’re called Miss Iles and you’re carrying luggage labelled thus, airline security incidents can result, as Tina May and Nikki Iles have discovered in their travels as arguably the UK’s leading jazz vocal and piano partnership.

Fortunately there’ll be no suspicious bags on airport tarmacs as May and Iles mark their twentieth anniversary with a Scottish tour this month because they’re travelling by road although, as Gloucester-born May says, despite having spent most of her childhood holidays in Scotland visiting her dad’s side of the family, she can still get the pair lost when they’re working up here.

May remembers her first public performance at a family gathering in Cambuslang when as six year old she was coaxed from under a chair to sing Puff the Magic Dragon. She has long since conquered her stage fright and can list student revues in Paris and Edinburgh with impressionist Rory Bremner on her CV alongside singing Come Fly with Me for the theme song of television docusoap Airline and, in jazz terms, the infinitely more prestigious experience of recording in Rudy Van Gelder’s legendary Englewood Cliffs studio in New Jersey, scene of countless recordings for the Impulse! and Blue Note labels, including John Coltrane’s classic A Love Supreme.

“My dad was worried about me when I was leaving school,” she says. “My mum had just died suddenly and my sister was going to be a doctor, so he wanted me to do something useful. I’d played clarinet and bass clarinet in the local youth orchestra and was interested in drama but I knuckled down and went to study French at Cardiff University.”

In Cardiff she heard trumpeter Harry ‘Sweets’ Edison and saxophonists Eddie ‘ Lockjaw’ Davis and Al Cohn at Welsh Jazz Society gigs and the seeds of her subsequent career were planted. These seeds began to flourish during a year’s study in Paris as part of her course when she met pianist Patrick Villanueva and the two struck up a friendship that continues to this day. Villaneuva had musician friends that included the incredible French double bassist Renaud Garcia-Fons and May found herself singing in the Paris jazz clubs with Garcia-Fons and the great American drummer Kenny Clarke among her early accompanists.

Rory Bremner happened to be on a year out from Kings College, teaching English in Paris at the same time as May was there and they met in café. Even then Bremner was displaying the talent that would bring him to national prominence (no mean impersonator herself, May imitates his take on My Funny Valentine, sung as My Funny Hesseltine in John Major’s voice). They hit it off and put a revue together called You Are Eifel but I Like You. May winces at the pun but slightly de-Frenchified and renamed Midnight Excess, the revue became their passport to the Edinburgh Fringe.

Back in Cardiff, May formed Frevo, a Latin American-influenced band with guitarist Dylan Fowler and played gigs including Bath Festival, where May was invited to sing with Brazilian guitarist-pianist Egberto Gismonti’s group. London beckoned, however, as the city of jazz opportunity and after working in theatre workshops by day and gigging by night, May sent a demo to an arts centre in Luton. She was looking for a gig but the organiser there ran a record label, 33 Records, and her recording career was born.

May went on to work with Humphrey Lyttelton, who resurrected her clarinet playing, and after adding lyrics to tunes by Weather Report keyboardist Joe Zawinul and saxophonist Bobby Watson, she was invited to put lyrics to tunes by pianist Ray Bryant, accompanist to singing greats Betty Carter, Carmen McRae and Aretha Franklin, which led to them recording together in Rudy Van Gelder’s New Jersey studio.

One of her most treasured memories, however, is of the night, twenty years ago, when she and Iles were pitched together for the first time in Yorkshire.

“There was an immediate affinity,” May says. “Nikki just seemed to know instinctively what to play and when, and that’s continued down the years. We don’t work together all the time because we both have other things that we go off and do separately but when we meet up we pick up where we left off immediately, so much so that we’ll finish each other’s musical phrases onstage. And offstage we have a hoot.”

Among May’s “other things” are her recordings for Pitlochry-based Hep Records, part three of which she’ll record in January and will be called Get Happy.

“I love singing ballads but jazz isn’t all about sadness,” she says. “I have no idea what Nikki and I will be playing on tour because we often decide while singing in the car on the way to the gig. There’ll be some slow songs but the main thing will be to connect with the audience and make everyone feel good.”

Tina May & Nikki Iles play the Blue Lamp, Aberdeen tonight [Thursday, September 3], Birnam Arts Centre (September 13), Traverse Theatre, Edinburgh (September 14), Carnegie Hall, Dunfermline (September 16), Nairn Dunbar Golf Club (September 17), Lyth Arts Centre, near Wick (September 18), and Hospitalfield House, Arbroath (September 19).