Kurt Elling: This cat can scat!

He's an all-time jazz great and has friends in very high places – but can Kurt Elling make us fall in love with vocal improvisation and its eccentricities?

Kurt Elling is giving musical directions to the Klüvers Big Band in Aarhus, Denmark. "If we've been doing our job right, then everybody's all groovy." To a tenor saxophonist: "You're gonna be so sexy out there, I'll just stay out of the way. All the ladies will be, 'Oh, woo hoo!'" And to the conductor: "You cut them off there, you dig?"

Kurt Elling is hip, all right. The old-school lingo of the jazz musician – "you cats", "yeah, baby" – springs from the lips of the 39-year-old Chicagoan as naturally as the great standards of the American songbook. He can phrase "In the Still of the Night" with that mixture of legato and drop-dead staccato that elevated Sinatra to the position of "Chairman of the Board". His mastery of the style would be enough to earn him the mainstream success of a Harry Connick Jr.

But while Elling is well known on the jazz circuit, in demand around the world, and has won Down Beat magazine's critics' poll for male vocalist every year for the past eight, he is not a household name. And that is because he has chosen a much more difficult route – that of the true jazz singer. Isn't Connick a jazz singer, it may be objected? Isn't Tony Bennett? Yes and no. They are both associated with jazz, sing the right kind of songs, and Connick is a more than competent pianist.

Truly to deserve the title of jazz singer, however, a vocalist must be able to contribute as much as any jazz instrumentalist. That means being able to improvise or, as it's called in singing terms, "scat". It's not enough to imbue a lyric with a particular sensibility or to be impossibly daring with a phrase, only then to stop and let a pianist or saxophonist take a solo; the jazz singer can do that himself – he can find " the melody that hasn't been sung yet", as Elling puts it.

A master vocalist in full flow bears scant relation to the gentle " doobie-doos" of Ella Fitzgerald or Cleo Laine. On stage at the Musikhuset in Aarhus, multi-syllabic torrents pour forth from Elling's mouth. At times, he throws his head back, eyes staring madly, and howls in an ear-piercing falsetto; at others, he growls with the darkness and depth of coal being crushed under a door.

This, along with his breathtaking technique, powers of invention and skills at vocalese (setting words to long, often highly complex, instrumental solos), is what makes Kurt Elling possibly the greatest jazz singer alive today, and certainly one of the all-time greats. He just happens to be a poet, philosophical thinker and friend of Democratic presidential hopeful Barack Obama as well.

"I couldn't say I'm an intimate of Barack's," says Elling when we meet the day after the performance, "but I've supported him since the time he ran for state senator. I'm pretty sure that I played his first political fundraiser. We sat and chatted for quite a while after that. And we'd bump into each other, because he was just around the corner from where I lived." Two years ago Elling bought from Obama the apartment in which he, his wife and their two-year-old daughter now live.

"When he's interviewed about what music he likes, he's been kind enough to say, ' Kurt Elling – he's a friend of mine,' which is nice to hear. That isn't why I support him, by the way." Elling can talk endlessly about politics, why Republicans are "buffoons" and how Obama has an ability to inspire similar to Kennedy. He's quite intense, be it on the failings of American foreign policy, his duty as an artist or religion (his father was Kapellmeister at the local Lutheran church, and Elling's lyric to part of John Coltrane's "Resolution" ranges over the major faiths).

There is humour, too. At the previous day's rehearsal he had the band falling about with laughter as he introduced the players in his version of trumpeter Clark Terry's "mumbles" routine, which comprises gobbledegook delivered with the fluency and purpose of normal speech. He also takes with good-natured bemusement the bizarre dining arrangements at the Ritz Hotel, where we lunch. We have not ordered any food; not, in fact, even looked at a menu. Nevertheless fully laden plates are delivered, assorted seafood, creamy mash and salad arranged around a pot of thick brown sauce. It looks like chocolate mousse. Elling dips a piece of scallop in. He chews it. The verdict? "It is chocolate mousse. Here's your salad, your main course and your dessert all on one plate. And the check is under the fish."

The jokes, while genuine, are asides, part of the varnish that makes Elling a slick performer. Underneath, he is a person of high seriousness. He read philosophy of religion as a graduate student at the University of Chicago, and considered working for the World Council of Churches or pursuing an academic career. He still has a profound sense of faith, although it is not necessarily conventional. "I see his point," he says, when Richard Dawkins' The God Delusion comes up. "It's easy to get tired of religious fundamentalists. They're such a bore. They have no sense of mystery. It's a drag, man."

You'd need to be serious to try to make a living out of the type of jazz singing Elling does. "A lot of people are put off by the idea of scat singing," he says. "Either that or it's something to be made fun of." There are two problems. "First, it's unusual. Second, too many people attempt it without doing their homework and give the rest of us a bad name."

Elling had sung in choirs all his life and already liked instrumental jazz. It was when a fellow student took him to see a performer even Elling now agrees can come across as "egregiously eccentric", that he began to realise his true vocation.

"One night someone said this guy, Mark Murphy, is on at a club in Minneapolis." Murphy, a master of scat from a previous generation, is not for the faint-hearted. Elling was bowled over. "It was heavy, beautiful, awesome, death-defying. It really gave me the example I needed. Mark is possessed, man, he's intense. But hey, why would you want to go halfway?"

College increasingly palled and the club scene – where Elling started "sitting in", making forays into the new territory of vocal improvisation – lured him from his studies. He left one credit shy of his degree and moved to a small basement apartment in the city – "about the size of this table", he says. He worked part-time, tending bar and moving furniture, while singing in the evenings. Within two years, he had been signed. "I was very lucky that more experienced musicians allowed me to caterwaul until I figured out what it was really about."

A decade and a half and numerous albums later, word has spread about this extraordinary performer to the point that his tours now take him to large concert halls. "It's still too much for some people," he says. "But you know what? Screw those people. My goal is to be really incredible by the time I'm 70. When I'm 70, I'm going to kick everyone's ass." He probably will, too. *

Kurt Elling's UK tour runs from Friday to 25 October, for more information: www.kurtelling.com. The album 'Nightmoves' is available now

The scat pack: Five of the best jazz vocal performances

Kurt Elling, 'Man in the Air'

Thrilling Coltrane covers, beautiful, thought-provoking originals by Elling and his pianist Laurence Hobgood – and some mad poetry too

Mark Murphy, 'Mark Murphy Sings'

The wild man of jazz singing reinvents Freddie Hubbard's classic "On the Red Clay" with support including the Brecker Brothers

Al Jarreau, 'Look to the Rainbow'

Jarreau at his best, with the definitive vocalese interpretation of " Take Five". What he could have been – he soon decided to take the commercial route

Dee Dee Bridgewater, 'In Montreux'

The feistiest of female singers, DDB shows why you should throw away your Norah Jones albums and listen to her swing like the clappers instead

Carmen McRae, 'Carmen Sings Monk'

Stately, majestic singing from McRae on vocalese versions of Thelonious Monk classics including "Blue Monk" and a lovely "Pannonica"