What is “Celtic music”? Obviously, the term doesn't describe the music of the ancient Celts, which hasn't survived in any recognizable form to modern times. The term is actually a rather loose one; it covers the traditional music of the Celtic countries: Ireland, Scotland, Wales, Brittany (in France), Galicia (in Spain) and areas which have come under their influence, such as the USA and the maritime provinces of Canada. It is also used for some newer music based on the tradition from these countries.
This music has evolved over a long period of time. Much of the repertory is known to have been current in the 18th and 19th centuries. Some is earlier in origin, and it is likely that some very old melodies and lyrics survive, adapted to modern forms.
Traditionally Celtic music had a solo form, but group performances have become dominant in the past 60 years. The most commonly used instruments include tin whistle, Irish flute, fiddle, uilleann pipes, concertina and accordion; with guitar, Irish bouzouki (a sort of mandolin), banjo and bodhrán (a kind of drum) playing a support role.