Celtic music is sometimes difficult to gauge for authenticity.  It is like the job of determining the particular species of rodents in the wilds.  You have to get closer, or listen closer for that matter, to have a better grasp.  Most of what we know about Celtic music was originally-transmitted through traditional means. Celtic instruments are the living relic of what remains to the once thriving Celtic music.  Various companies and music stores have ventured into the reproduction of these unique instruments.  True musicians of various nationalities can claim influence of large extent from Celtic instruments.