A number of leading musicians have signed a letter in today’s Guardian calling on Chetham’s School of Music and other specialist music institutions to conduct a full independent inquiry into alleged sexual abuse at the Manchester school.

The letter – initially a petition set up by Ian Pace, pianist and himself a Chetham’s alumni – has been signed by 238 former alumni, including pianist Paul Lewis, cellist Matthew Barley, pianist Peter Donohoe and conductor Daniel Harding. Other musicians who have signed the petition include composers Richard Barrett and Sally Beamish, violinist Lisa Batiashvili, cellist Steven Isserlis, oboists Douglas Boyd and Nicholas Daniel, pianists Imogen Cooper, Leslie Howard, Steven Osborne and Danny Driver, and tenor Mark Padmore.

The letter follows the conviction earlier this month of the school’s former music director Michael Brewer – who most recently held the post of artistic director of the National Youth Choirs of Great Britain and the World Youth Choir – for indecently assaulting a pupil between 1978 and 1982. The victim of his abuse, Frances Andrade, who gave evidence in the trial, was later found to have killed herself.

It is also today reported that Malcolm Layfield, head of strings at the Royal Northern College of Music, also in Manchester, has left his post amid allegations over his conduct with pupils. Pianist Martin Roscoe, who resigned from the RNCM over Layfield’s appointment in 2002, is a further signatory to Ian Pace's petition.

The Guardian letter begins: ‘Following the conviction of the former director of music, Michael Brewer, the tragic death of Frances Andrade, and extensive testimonies in the press of other abuse, it is clear that there should now be a full independent inquiry into the alleged sexual and psychological abuse by Chetham's staff since the establishment of the institution as a music school in 1969. Such an inquiry would ideally extend to other institutions as well, some of which have also been the subject of allegations of abuse.’

It calls on ‘senior members of staff from that time to account for what appears to be the severe failure of the school system to protect its pupils from those who exploited their positions of power’.