Granville Public School pupils were on song during rehearsals for Music Count Us In.
The 547 pupils from kindergarten to year 6 will raise their voices to sing specially written track Keep On simultaneously with their peers across Australia at 12.30pm on Thursday, October 31.
Kindergarten teacher Rebecca Shaw said it was the first year the school had registered for the Music Council of Australia event, which aims to promote music education in schools.
"Over the past few years our school has really [increased the] music programs we have," she said.
"We have two choirs and we have a glee club now. We use xylophones with infants and year 5 and 6 students learn recorder.
"Parents volunteer to come in and teach music as well.
"I think by having these kind of opportunities the kids get to showcase their talents."
Keep On was written by four high school students who were guided by singer-songwriter Katie Noonan, with production by John Foreman.
"It's a very empowering song," Ms Shaw said. "It's all about what they want to be when they grow up. So it gives them prompts and ideas for their writing and to be a bit more creative.
"In kindergarten you start off with stories and rhymes and poems and things like that, and music helps with their working memory.
"A lot of the musical activities that we do are group-based activities so they're helping children to develop social skills."