Mozart wrote the piece to celebrate his wedding

The Mass in C minor has been painstakingly reconstructed over the past two years by Phil Wilby, of the University of Leeds.

Prof Wilby was assisted by colleague Peter Holman and Father Peter Allan from the Community of the Resurrection in Mirfield who pieced together the end of the score using clues from previous Mozart works.

The newly-completed piece will be performed on period instruments at the university on Sunday afternoon.

This is Mozart at his very finest Professor Phil Wilby

Prof Wilby said: "He provided us with a wonderful beginning but no ending.

"He wrote the piece to show off his skill and the talents of his wife, Constanza Weber, who sang the soprano part.

"It was his masterpiece from the church music point of view.

"This is Mozart at his very finest."

Father Allan said: "We hope that we've managed to fulfil Mozart's first intentions as far as possible.

"The project has been arduous and long, but has finally provided us with much food for thought and a possible score for Mozart's liturgical masterpiece, a thanksgiving mass for marriage."

Mozart vowed to his father to complete the two-thirds finished mass, but never did so.

The unfinished mass was first performed in the Abbey church of St Peter in Salzburg on 26 October 1783.