The capital city of Luxembourg was the home of the 11th Eurovision Song Contest. The rules for the contest were changed and national juries could include music experts again. The major change was that a rule was introduced stipulating that songs had to be performed in one of the official languages of the participating country. During the dress rehearsal, the Italian participant Domenico Modugno was not satisfied with the orchestra and left the stage in anger. It was uncertain if he was going to perform during the live show, but he sang his song Dio Come Ti Amo after all. The song later became a huge success in South America for Gigliola Cinquetti, the winner of the 1964 Eurovision Song Contest.