Then, and only then, does he probe more deeply into the crafting and tuning necessary for it to find its voice. Orchestral stringed instruments also come from trees, he points out, "but they're more manufactured and hand-crafted". He settles on the cello as the perfect counterpart to the didgeridoo, "because you can do didgeridoo bowings and seagull effects on it".
A moving documentary in the Australian Story series, available online through the ABC, tells this man's story. It opens on the banks of the Seine, with Barton and his mother, Delmae, strolling among artists' stalls. Notably, his first words are: "The tucker's all right at the restaurant, eh?"
Sculthorpe is quite a presence in the film and Barton smiles, remembering his friend "sitting in the dusk, in his chair at Woollahra". The composer extolls this young man who has played a didgeridoo central role in so many of his works, including the 2004 Requiem. He says that "having William and the didgeridoo in my life is almost like bringing my music home".
Barton first played Sculthorpe's music in 2001 with the Goldner Quartet at Townsville's Australian Festival of Chamber Music. The two men met the following year.
"Sculthorpe walked into the room and that's when the magic happened," says Barton. "This was the beginning of my life in the classical music world, even though I had had my first orchestral concert, four years before that, when I was 17. Peter's music is so bound up with our country's landscape. He wrote what has become the quintessential Australian music, bot for the nation and for the world."
Barton has taken the compositions of Sculthorpe and other Australian composers, including himself, around the world. He mentions appearances at Carnegie Hall and the Berlin Philharmonie. "Maybe playing with the Vienna Philharmonic would be another high," he muses. "You don't want to gig every night with the same orchestra."
He is just back from Europe, where he played his own Kalkadungu in St Petersburg, and being "the first Aboriginal composer to play with the Mariinsky Orchestra must be another step in the right direction".
Tomorrow, at the Auckland Art Gallery, Barton will offer a free demonstration of his music and instruments to whet our appetites for Thursday's smorgasbord.
What: Auckland Philharmonia Orchestra
Where and when: Auckland Town Hall, Thursday at 8pm
What: William Barton solo
Where and when: Auckland Art Gallery, main atrium, tomorrow at noon