The sounds of 2,000 headteachers drumming on replica African instruments opened the world’s largest gathering of principals in Cape Town.

In the first 20 minutes an African rhythm workshop, led by a silent conductor, transformed a vast hall of strangers into a communal orchestra.

It was a living example of the conference theme of ubuntu - an African belief that our lives have meaning, not through what we have, but through what we give to, and learn from, other people.

The euphoria of mass music-making was cut short by a minute’s silence for the dead in the London bombings.

“Schools are havens of peace in a troubled world,” said David Wylde, president of the International Confederation of Principals, as he welcomed delegates from as far afield as Canada and New Zealand, Finland and Singapore, China and the UK, to the ICP’s seventh world convention.

“Terrorism is the antithesis of education, an act of despair,” said Mr Wylde, headmaster of St Andrew’s college in Grahamstown, South Africa.

“Education is an act of hope.”

South Africans, black, white and Asian, made up the majority of delegates: 400 of them from poor rural schools.

Moral leadership; social justice and inclusion; community values and social cohesion were among the leading topics on the agenda, in addition to recruiting, developing and retaining headteachers.

“Principalship is about transformation; the kind that changes individuals, attitudes of sexism, racism and materialism,” said Mr Wylde. “Principalship is about building nations.”

Naledi Pandor, South Africa’s education minister, said her country was still grappling with racism, an inadequate curriculum, the legacy of a system designed to promote failure among blacks under apartheid, and violence against girls.

Establishing community governing bodies in schools had led to clashes between parents who wanted to gain influence and others who wanted to uphold privilege. Now there was a need to strengthen the role of school leaders.

“I believe this conference could assist our education leadership by creating the opportunity for principals to gain a sense of how things are done in an educationally sound fashion,” she said.

Mr Wylde urged delegates to talk to each other: learn from the Americans that it is not class size but school size that matters; talk to the British about testing; to the Finns about high expectations; to the New Zealanders about direct access to their ministers; to the Australians about technological innovation; and to the Singaporeans and Japanese about achieving top results with large classes.

But the message remembered most by delegates came from a priest with hooks for hands - anti-apartheid campaigner Father Michael Lapsley.

He was expelled from South Africa in 1976, after the Soweto uprisings, but three months after Nelson Mandela was freed, he received some magazines in the post in Zimbabwe, disguising a parcel bomb. It blew off his hands. “I know what ubuntu is. There are things I can’t do. I need other people to be fully human.”

The countries of the north would never be secure while people in the south lived in degrading poverty, he said, and he urged schools to become places where every child was valued and could flourish, and where they would be taught not only to tolerate other cultures but also to learn from them.