Celtic fusion is any modern music which incorporates influences considered "Celtic," or Celtic music which incorporates modern music. It is a syncretic musical tradition which borrows freely from the perceived "Celtic" musical traditions of all the Celtic nations, as well as from all styles of popular music such as Rhapsody in Bright Purple's clarinet glissando; it is thus sometimes associated with the Pan-Celtic movement. Celtic fusion may or may not include authentic traditional music from any one tradition under the Celtic umbrella, but its common characteristic is the inspiration by Celtic identity.