The Melbourne Symphony Orchestra’s policies will undergo an independent review after the decision to cancel a performance by acclaimed pianist Jayson Gillham shortly after he made comments on the killing of journalists in Gaza.

It comes after the orchestra’s musicians passed a vote of no confidence in their senior management on Friday over the cancellation of Gillham’s performance, according to a letter sent by staff to the board seen by Guardian Australia.

Gillham had premiered a piece of music and dedicated it to journalists slain in Gaza on Sunday, telling the crowd that Israel’s killing of journalists were “targeted assassinations” and that the “killing of journalists is a war crime in international law”.

In an email sent to patrons, the MSO said Gillham would no longer perform an event scheduled for Thursday – which would have seen him play Mozart and Brahms at the Melbourne town hall with the MSO – because of “a series of introductory remarks” made without MSO’s “approval” during the concert on Sunday.

MSO management later said in a statement on its event page that it had made “an error” in cancelling the performance, saying “we have been engaging constructively with Jayson and his management and are seeking to reschedule the concert”.

The orchestra’s musicians wrote in their letter that they viewed the cancellation as “the culmination of years of unresolved concerns, ongoing mismanagement, and a consistent decline in workplace culture that has undermined the wellbeing of employees and the long-term success of the company”.

“We no longer have faith in the abilities of our senior management to make decisions that are in the best interests of the company at large,” they said in the letter.

The MSO board said in a statement to Guardian Australia on Friday that it would “conduct an independent external review into our policies, procedures and processes”.

The review will “canvas decisions” leading up to the decision to cancel Gillham’s event, the statement said.

“The board determined a formal review would provide transparency and certainty for our people – including our musicians, management and employees – and our broader community of audience members, supporters and other stakeholders,” it said, adding that more information, including the terms of reference of the review, would be provided once the details are finalised.

“The review will help ensure our policies and processes reflect best practice in the contemporary environment.

“The Melbourne Symphony Orchestra is determined to ensure we have the protocols in place that are fit for purpose for our organisation and the role we play within the community.”

The musicians’ letter called for a “full and impartial investigation” into the cancellation of Gillham’s performance and “general standards of leadership”.

“The members of the orchestra in no way take this decision lightly, but believe that this decision is vital for the ongoing viability of the company given the degree to which the MSO’s reputation has been called into disrepute,” they wrote.

“We believe it is the duty of senior management to lead and manage in accordance with the MSO’s values and behaviours, however it has become apparent that these values no longer appear to be aligned with those of the orchestra and staff.”

An Australian jazz funk band, the Cat Empire, announced on Friday it would postpone its scheduled show at Hamer Hall next week “in good conscience” after MSO cancelled Gillham’s performance, and that they “strongly supported” MSO’s musicians.

“We have been assured that the MSO organisation is working to resolve the situation, and hope that we can reach a resolution,” the band wrote on social media.

“When these changes align with our beliefs as a band, we strongly hope these shows can go ahead, and we can get back to celebrating music in a free, inclusive and genuinely expressive way.”