Christchurch victims

There was a sense of grief - but also one of defiance - in the air as almost 90 people spoke about the incident that killed 51 people in Christchurch.

Dozens more were injured when Tarrant opened fire on two mosques last year.

He has chosen not to speak in court before his sentencing on Thursday.

The 29-year-old Australian has pleaded guilty to 51 counts of murder, 40 attempted murders and one charge of terrorism.

He faces life in prison, possibly without parole - a sentence never before imposed in New Zealand.

Just over three weeks ago, the students were told they would not be performing at Polyfest because of the events in Christchurch.

On Sunday, more than 50 boys took to the stage at the school's gala day on its campus in the suburb of Glendowie.

One of the parents, Sharon Swann, said the boys agreed that all donations made at the performance would go to the victims of the Christchurch attacks.

The group had missed out on other chances to perform since 15 March, she said.