Sistine Chapel Choir to sing with Westminster Abbey Choir

(CBS/AP) The Sistine Chapel Choir, whose boys and men sing for the pope at all his Masses, is joining forces with the Westminster Abbey Choir, the world-renowned chorus that last year performed at the wedding of Prince William and Kate, Duchess of Cambridge.

The two choirs will sing together at a special papal Mass on Friday in St. Peter's Basilica, a historic event seen as a perfect symbol of Christian harmony after centuries of discord.

It's the first time in its 500-plus year history that the pope's personal choir will sing as a single chorus with another choir, let alone one from the breakaway Anglican church.

The symbolism of the united choirs is enormous, particularly given Pope Benedict XVI's stated aim of trying to unite all Christians.

Anglicans split from Rome in 1534 after English King Henry VIII was refused a marriage annulment. A half-millennium later, the two churches remain divided on a host of issues, especially female bishops and openly gay priests.

"In diversity you can find points of unity," said Monsignor Massimo Palombella, the choirmaster of the Sistine Chapel Choir. "And I dare say, it's not just that you can find it, you must find points of unity. To do this, we use culture."