I knew Sydney very well and found him to be a very decent English type in the mould of Flanders and Swan and his songs were usually set to obvious trad tunes. He was a committed Christian and although not overtly anti-semetic, his creed would not allow him to agree with the Jewish faith. If only the melody to Lord of the Dance is performed and named as a Gift to be Simple then it is not in copyright but call it Lord of the Dance, then Sydney's Estate holds the rights.