Multiple soloist and break-dancer Billy Gibbings-John is on crutches after injuring his knee while busking with his dance crew on the street in Melbourne.

But after discovering the news at yesterday's final rehearsal, choreographer and artistic director Megan Beckwith said that the show would go on.

"We were working under pressure to re-arrange the performance," she said.

"We've had another two girls step in to share the role.

"Billy has severely bruised his kneecap, and broken some blood vessels."

But he will still appear on stage, on crutches, as a broken toy.

Ms Beckwith said she was proud of the students' final rehearsal.