Urban said on Thursday that he grew up listening to country music in Australia due to his dad who took him to see Cash when he was 5-years-old.
"That kind of crowd when you're 5-years-old, it's insane. They were hammered beyond hammered, the whole audience including my dad," the country star told Colbert.
The concert was held inside an old boxing venue in Brisbane which could fit 5,000 people.
"It was like you know, a stadium to me and this crowd was so noisy and intense and rowdy," Urban said.
"I remember this guy walking out on stage with a guitar and a spotlight and then he talked and the whole crowd went into this quiet hush," he continued. "It was amazing."
Urban mentioned how he wishes he could have told the late Cash about his experience.
The singer also performed live his new single "God Whispered Your Name" which will appear on an upcoming album. Urban last released Graffiti U in 2018.