Sarah Lambert, a Wollongong singer and choir director, is calling for local people to join her Choir For Change, the finale to the Boundless Plains to Share concert at City Diggers on June 20. The event closes the curtain on a string of Refugee Week events in Wollongong, from a soccer competition to a multicultural community dinner, and will raise funds for the Asylum Seeker Resource Centre.

"I've been watching what's happening with offshore refugee processing, kids behind barbed wire and being treated horrifically, and thinking how hard it was to bear this was happening in my country," Ms Lambert said.

"I thought I would stick with my strengths in music, and organise a concert to help do something about it."

Ms Lambert said several organised choirs had already offered their voices to her mass choir, and she is calling on the Illawarra community to get involved. A rehearsal will be held at City Diggers on May 29 from 6pm, with others on June 5, 12 and 19.

"You don't have to be a good singer. We are doing really simple songs."

The Illawarra Union Singers are one of the groups participating in the choir. Founding member Mairi Petersen, who has acted as a mentor and "mum" to dozens of refugees, said she hoped the concert could spread information about refugee treatment in Australia.

More concert information can be found at boundlessplains.org.