Celticism came to be associated with the bagpipe and the harp. The harp is considered to be the national instrument of Wales and is used to accompany penillion singing (or cerdd dant) where the harpist plays a melody and the singer sings in counterpoint to it. The roots revival, applied to Celtic music, has brought much inter-Celtic cross-fertilisation, as, for instance, the revival by Welsh musicians of the use of the mediaeval Welsh bagpipe under the influence of the Breton "binioù", Irish "uillean" pipes and famous Scottish pipes, or the Scots have revived the "bodhran" from Irish influence. Charles le Goffic introduced the Scottish Highland pipes to Brittany.