WAV you again express your ignorance.
I employ many different techniques.,including playing the tune,in fact IF you bothered to listen to my cds and clips on you tube,there are occasions when I play the tune.When singing.
yes i frequently play the tune,here are some examples,adieu sweet lovely nancy[you tube],live not where i love, bogies bonny belle,streams of lovely nancy.,Barbara Allen[you tube],ball of yarn[youtube].just as the tideis flowing [myspace]
but you see because Iam skilled,I am playing the tune with chords.
most other professional performers,SteveTurner,Louis killen,keith kendrick, Damien Barber,do the same thing play melody with chords.they also play chords without melody,when they choose.
I also play single line harmony with my voice.
you are ignorant about the concertina too,it was only invented in 1843,so it is a victorian instrument,people have not been playing it for centuries.