I read somwhere that O'carolan was no great shakes as a harpist and that , if he had been as good as some of his contemporaries, his music would never have been remembered.
Most Irish harpists at the time started at a very early age ;Carolan only took up playing after he went blind at the age of fourteen . To make up for his lack of skill he started composing. His compositions were written down and it was for them that he became famous.