In 1957, Callas was starring as Amina in "La sonnambula" at the Edinburgh International Festival with the forces of La Scala. Her contract was for four performances, but due to the great success of the series, La Scala decided to put on a fifth performance. Callas told the La Scala officials that she was physically exhausted and that she had already committed to a previous engagement, a party thrown for her by her friend Elsa Maxwell in Venice. Despite this, La Scala announced a fifth performance, with Callas billed as Amina. Callas refused to stay and went on to Venice. Despite the fact that she had fulfilled her contract, she was accused of walking out on La Scala and the festival. La Scala officials did not defend Callas or inform the press that the additional performance was not approved by Callas. Renata Scotto took over the part, which was the start of her international career.