If Ian Shaw was ever to go on Mastermind, his specialist subject would have to be the songs of Joni Mitchell.
Shaw, who brings his Sings Joni Mitchell show to the inaugural British Vocal Jazz Festival next week, seems to have the Canadian master songwriter's entire collection of lyrics on instant recall.
In conversation, a detour into the Welsh-born jazz singer's experiences as a stand-up comedian and whether he can mix that art form with Mitchell's peerless and highly personal songs of the human condition, solicits a line from Be Cool: "Keep things light. Keep your worries out of sight, and play it cool, play it cool, fifty-fifty fire and ice."
Later, on the subject of songs that he has difficulty singing, Shaw delivers a line from Amelia - "where some have found their paradise others just come to harm" - also as if onstage, although in the story he's illustrating he couldn't actually see the music on the stand for the tears that had welled up in his eyes.
"I'm a huge fan, yes," he says almost needlessly. "I find things in her songs that I haven't been able to find in the jazz singer's Bible, the Great American Songbook. There are songs of aching disappointment, journeying, consolation, and while other writers have covered these themes and feelings, something in Joni's writing just seems to resonate within me. Plus, of course, she writes fantastic melodies to carry these words."
Shaw first came across Mitchell's music as a 16-year-old when he happened across her Blue album in the local library on the way home from school on the last day of his sixth-form term.
He was already listening to Sarah Vaughan, Frank Sinatra and Miles Davis, as well as artists who were perhaps more typical 1970s teenager fare like T.Rex, David Bowie and Supertramp, and he was first drawn to the image of Mitchell, with her sharp cheekbones, on Blue's cover.
His fascination for Mitchell's lyrics came soon afterwards as he walked home, drinking in images from the lyrics printed on the inside of the gatefold sleeve such as "The bed's too big, the frying pan's too wide" from My Old Man.
"I couldn't imagine how someone who was writing lines like that and songs about dark cafes and needles, guns and grass would sound," he says. "They were rock 'n' roll words mixed into images so specific, so confessional, so domestic as to be straight from a diary kept in a drawer. Then I got the album home and played it and that was it. I had to find every other record she'd made."
In 2006, some 30 years after he'd begun his search into the world Mitchell describes with such precision, Shaw recorded the album Drawn to All Things, a collection of 14 Mitchell songs, which his record company, Linn, had some influence on, although they couldn't persuade him to sing Big Yellow Taxi.
"No, I drew the line at singing about a big yellow taxi taking away my old man," he says. "Both Sides Now I could absolutely understand them wanting to include and I love that song. I think it's the story of everybody's life. I could easily record a volume two and three right now. In fact, I've been looking at my next album and I think, what Joni song should I do and I end up thinking, oh, just make it all Joni songs.
"But it's a bit like the live show. I wonder am I qualified to sing these songs and if people turn up, are they going to be disappointed to find it's not someone who looks like Joni singing but this overweight, bald, middle aged gay man?"
For Shaw, who has performed the songs he'll be singing in various situations, including with just his voice and a guitarist and in orchestral settings arranged by his partner in another of the British Vocal Jazz Festival concerts, trumpeter Guy Barker, singing Mitchell's songs to his own piano accompaniment is both natural and a challenge.
"I look at the songbooks and think, thank god I'm not a guitar player because she seems to find chords on the guitar that no man has ever played before," he says.
"But I think the trick is to find your own way of singing and playing these songs. Nobody can do them like her anyway and I'll put them into context with my own stories, throw in a little stand-up comedy, keep things light because although there's a lot of sadness in her songs, Joni's always laughing when you see her interviewed or in concert."
Ian Shaw sings Joni Mitchell on Wednesday August 7 and sings song from the movies with Guy Barker on August 22. The British Vocal Jazz Festival, which includes Carol Kidd, Claire Martin and Christine Tobin, is at Le Monde, 16 George Street, Edinburgh, August 5 - 26.