A singer must have a basic tune to sing to surely ~ the words are sung to music, that is a tune ~ this I understand as far as folk is concerned (the tune) in traditional unaccompanied terms will and does change with each performance (that is where sung unaccompanied!)

The singer is making music every time he/she sings ~ the tune is basic ~ yes add an instrument and the tune as a vehicle will certainly be more uniform but will still differ even only to a small degree ~ am instrument is not needed to make music!

The voice is an instrument conveying both tune and words or mouth sounds together!

Ray

So a singer is a musician!! sheesh