It is almost impossible to 'insert' a new tune into Irish trad since all the best themes are already taken, centuries of fiddlers/whistlers etc working different scales etc., You may like to read a little on this. For example Miss Mc Cloud's Reel - a fiddle tune - got it's 1 st few bars from a string crossing excercise which long predates the Reel as a folk dance.

Similar topic is why is Trad Jazz not popular as it used be? Why is modern jazz 'Modern' Why is Rap so popular? Why is Classical Music so errrr snooty? Why are classical musicians so boring? Why is Choir music so 'Conservative' Why is Celtic music so trendy? What is a social trend? How do current events interact with popular taste? Why are Mudcateers so enthusiastic about folk?