TOMMY Smith and Brian Kellock have become used to seeing each other across the stage as they play music by Duke Ellington and Count Basie. The director and pianist respectively in this weekend’s Scottish National Jazz Orchestra concerts of contrasting Ellington and Basie works have a history both individually and collectively with the music of these two jazz giants.

In the Spirit of Duke, the internationally acclaimed album that featured Smith and Kellock in the same roles as they’re about to take up again with the orchestra, is just one example of their larger scale investigations of the Ellington repertoire. And in their concerts as a duo they have been known to play a programme entirely dedicated to the music of Ellington and his amanuensis, composer and arranger Billy Strayhorn.

“There’s no real mystery as to why we keep going back to Ellington in particular,” says Smith down the line from Bath, where the quartet he formed in dedication to saxophone icon John Coltrane has just finished an ecstatically received UK tour. “With the SNJO we’ve performed a number of the suites Ellington composed, as well as doing the more general survey of his music with the In the Spirit of Duke album and concerts. And we still have more to do – the New Orleans Suite, for example, and his Sacred Concert. He was, quite simply, one of the most, if not the most, prolific composers in jazz and the quality of his – and Strayhorn’s – writing was so consistently high that you want to keep exploring it.”

The upcoming concerts, says Smith, will highlight the difference between Ellington and Basie, although both he and Kellock feel that the shorthand assessment in jazz – if you want sophistication you go to Ellington and if it’s groove you’re after, it’s Basie – undersells both musicians as bandleaders.

“Basie’s music generally is quite simple and focuses more on swing and creating a sense of fun,” says Smith, “whereas Ellington’s does tend to be more serious. The Ellington work we’re playing this weekend, Black, Brown and Beige highlights the African-American experience of slavery, emancipation and continued marginalisation. It was his first long-form composition, or suite, and very ambitious for a jazz composer in 1943. But at the same time, Ellington could groove – think of all those train rhythms that informed his music due to the amount of travelling they did as a band – and the arrangements Basie commissioned from Neal Hefti for the Atomic Mr Basie, which forms the second half of the concerts, are by no means unsophisticated.”

Both Smith and Kellock have experience of not only playing Ellington’s music but of playing it with musicians with first-hand experience of the Ellington band. Back in 1999, Smith was invited by his Swiss friend, saxophonist Fritz Renold to fill the chair once occupied by Ellington Orchestra legend Paul Gonsalves in a band that included former Ellington players Brit Woodman, Buster Cooper, Aaron Bell, John Lamb and Barry Lee Hall. It was, he recalls, overwhelming to sit in such illustrious company and yet thrilling to be with such great musicians and hear their stories about playing with Ellington

Joe Temperley, the Fife-born baritone saxophonist, filled his hero, Harry Carney’s role in the Ellington band after Ellington himself had passed on but he was able to give Kellock a strong impression of what it was like to play the music, even under Duke’s son, Mercer.

“Joe revered and adored Ellington’s music,” says Kellock, who worked with Temperley often and regards their tour as a duo, not long before Temperley died, with special affection. “He was, quite rightly, an absolute stickler for playing exactly the right notes and chords. He also didn’t want any extraneous accompaniment, and that sort of underplaying is good training for playing Basie’s music too.”

Kellock is particularly enthusiastic about playing The Atomic Mr Basie, even if he finds some of the tunes – all hits, as far as he’s concerned – difficult to play.

“They’re not hard in the sense that you have to have great technique to get round the melodies,” he says. “A tune like Lil Darlin’, for example – it’s a gorgeous tune and you have to be right in the groove from start to finish. More importantly, though, because it’s such an understated melody, you have to resist the temptation to overplay. It’s really tempting to fill the spaces in between the notes but you come to realise that the spaces are actually more than half of the tune. It’s fantastic writing by Neal Hefti and the arrangement is brilliant because it has amazing dynamics, from super-super-soft to super loud.”

Kellock came late to Ellington. He reckons he was in his thirties before venturing seriously into Ellington’s music and he missed out on the opportunity to play with Ellington musicians such as trombonist Al Grey, who was a familiar visitor to Edinburgh Jazz Festival. He well remembers many youthful efforts at playing another of the Atomic Mr Basie hits, however, The Kid from Red Bank.

“I must have played that twenty million times – and probably ruined it just as often - in different big bands when I was just starting to get jazz gigs,” he says with typical self-deprecation. “At a certain point, having played it a lot, I went back and listened to Basie doing it and it was an education. He gets into this heavy stride pattern and the rhythm section is just unstoppable but again, there’s that sense of economy that’s the Basie trademark.”

Kellocl also notes that Basie’s sense of economy – and Ellington’s too – extended to laying out (jazz parlance for not playing) for long periods. Both bandleaders would unerringly return at exactly the right moment, though, so Kellock is aware that he will have to keep his concentration throughout the concerts.

For Smith, who will take his customary chair in the saxophone section as well as conducting with his usual light touch, presenting Ellington and Basie in the same concert brings up running order considerations. The SNJO has an impressive history of getting into character over twenty-three years of concerts that have covered big band jazz from Glenn Miller to Stan Kenton and Benny Goodman to Buddy Rich. There have been programmes of European chamber jazz, jazz-rock, rambunctious tributes to Charles Mingus, a foray into Japanese culture with a taiko drum troupe, and free-wheeling new works by composers including the English pianist Keith Tippett.

“Black, Brown and Beige addresses issues that, with the black lives matter campaign, are unfortunately just as current now as they were when Ellington wrote it,” says Smith. “So the question arose: do we give the audience the more easily digested Basie material first and then play Ellington when everyone’s settled down? Or do we give them the thought-provoking piece when they’re fresh and then whoop it up it in the second half? We’ve gone for the latter option but there might be room for a change of plan depending on how things go.”

The Scottish National Jazz Orchestra plays Duke Ellington’s Black, Brown and Beige and Count Basie’s The Atomic Mr Basie at Usher Hall, Edinburgh on Thursday, December 6; Glasgow Royal Concert Hall on Friday, December 7; and Eden Court, Inverness on Saturday, December 8.