In traditional music the tunes are usually passed on by listening and playing... and not a dot in sight! That makes it difficult for people who are trained to read music and play their instrument accordingly. These days most of the tunes are written down and can be learned effectively enough this way. A traditional purist may say that a tune can't have the same feel if it is learnt by the reading notes but in a lot of cases there is no choice but to learn a tune this way. My view is to learn any way available, if both systems can be used all the better. If someone is enthusiastic, persistent and patient enough, the music will come through in it's own way, with it's own quality.