When it launched in 2015, Tarnanthi was already the largest contemporary Aboriginal and Torres Strait Islander arts festival in the country. Since then, three quarters of a million people have attended the festival’s exhibitions and associated events. It’s been possible to identify themes in each iteration, but for artistic director Nici Cumpston the guiding principle is that exhibiting artists have complete freedom. She explains that tarnanthi is a Kaurna word meaning “to rise, come forth, spring up or appear”.

“Tarnanthi is the theme of the festival because it enables the artist’s voice to do what it does best without the constraints of a theme.” The result is a festival whose scope has grown steadily each year; the latest program launches this month with more than 1000 artists exhibiting works across the Art Gallery of South Australia and 30 partner venues around the state. The festival provides a vital forum at a time when “there are very few opportunities for Aboriginal and Torres Strait Islander people to have a voice,” says Cumpston. Exhibiting artists range from 15 to 81 years of age, with works in painting, photography, printmaking, sculpture, moving image, textiles, performance and more.

Among the far-reaching pieces on display are a comic book drawn by a teenager from Port Hedland, a film by the women of APY Lands arts centre Iwantja Arts juxtaposing traditional lore and Western pop icons such as Dolly Parton and Cher, and Blood On the Dance Floor, “a work of autobiographical theatre” inspired by an HIV diagnosis.

Bunha-bunhanga: Aboriginal agriculture in the south-east is “the first ever representation through visual art of the groundbreaking research of Uncle Bruce Pascoe and award-winning author Bill Gammage into precolonial land-use practices”, says Cumpston. The work by Wiradjuri/ Kamilaroi artist Jonathan Jones brings together rarely seen tools used by Aboriginal people to tend the land and early colonial artworks from collections in the gallery’s Elder Wing. The project will be exhibited at the Botanic Gardens’ museum of economic botany.

Elsewhere, there are works addressing topics such as the plight of Aboriginal Vietnam vets, and the impacts on local communities of proposed oil drilling in the Great Australian Bight. The result is an incredibly far-ranging program that, says Cumpston, shows “Aboriginal and Torres Strait Islander artists are diverse and broad-thinking like any contemporary artists”.

Perhaps the most eye-catching pieces are Ryan Presley’s redesigned bank notes. His Blood Money Dollars replace the mostly white figures on our currency with leading Aboriginal figures. They can be bought at an exchange rate that’s constantly changing, but they’re always valued higher than legal tender. For Cumpston, the notes – which are based on highly detailed large-scale watercolours – are a way of “honouring and celebrating people who have been marginalised so they can be honoured and celebrated by mainstream society”. Money raised will go to Aboriginal youth programs.

Presley’s blood money dollars aren’t the only things you can take home. The popular Tarnanthi Art Fair at Tandanya will once again provide attendees with the chance to meet artists and buy works directly. More than 40 arts centres from across five states will be represented, and because the artists attend fee free, with travel expenses paid, all proceeds from the sales go directly to artists and art centres.

As a Barkindji woman and accomplished artist herself, Cumpston is wildly enthusiastic about these outcomes. That background has greatly influenced her approach to collaborating with other artists. She describes listening as both “underrated” and “an essential element of Tarnanthi’s approach”.

This approach means that Tarnanthi is not a feel-good festival dedicated to patting audiences on the back, but a deeply thoughtful and provocative collection of works. Like all great exhibitions, it’s an invitation to broaden your perspective. “This isn’t only about the viewer understanding what they are seeing in front of them,” Cumpston says. “It is about challenging people to look deeper and to listen, really listen, and hear what is being said and expressed.”

Tarnanthi launches at the Art Gallery of South Australia on October 17. Guests include internationally acclaimed Yolŋu artist and ceremonial leader, Djambawa Marawili AM and award-winning Yolŋu rapper Baker Boy. There will also be performances by artists from the Tiwi Islands and from north-east Arnhem Land.

The exhibition runs from October 18 to January 27.