In 1893, at the age of twenty-four, he moved to Belfast, where he opened a music store, but the venture failed, and he became the organist of a small parish in the city, the Holy Family Church, Wellington Place.
[2] He entered an anthem, O God of My Salvation for contralto and chorus, for the 1897 Dublin Feis Ceoil and won; on this occasion he heard folk song arrangements of Charles Villiers Stanford and others for the first time.
[5] Ill-suited for administrative tasks, he relinquished the post after one year and returned to Belfast, which after the Irish Civil War had become the capital of Northern Ireland.
Despite his mixed German/Welsh/English background, the events of the 1913 Dublin Lock-out, the outbreak of World War I, and the 1916 Easter Rising radicalised him, turning him into an Irish nationalist.
When Hardebeck died in 1945, a Radio Éireann-sponsored symphony concert, held in the Capitol Theatre in Dublin, began with a sympathetic performance of his orchestral variations upon Seoithín Seó.
The church was packed; various government ministers, the Lord Mayor and representatives of the President and of Éamon de Valera were there.
Cantata Songs, with piano accompaniment Choral Instrumental music Though uncredited, Carl Hardebeck's satirical ballad The Ould Piper is featured prominently in Pasolini's film The Canterbury Tales.
The ballad is about an old piper from Ballymoney named Allen Hoare, who manages to annoy both Moses and Satan with his terrible singing.