The fact is that every song or tune is based on some previous song or tune. Dark Island itself was apparently consciously written to conform with a style in which hundreds of similar songs were written, and the composer (in my opinion correctly) didn't feel that he needed to acknowledge that tradition, simply because it was obvious. Indeed, it being written for a TV programme, an atonal, rhythmically complex exploration of the fringes of meaning wouldn't have filled the bill quite as well.

As for the tune, has anyone noticed the similarities between this tune and another song of exile by a composer who never left the area, Cliffs of Dooneen?