yes,Jim,
because I understood what she meant, she is looking at singing from the perspective of an unaccompanied traditional singer,who was capable of interpreting long ballads,something Tommy Makem didnt attempt to do,and probably couldnt do,I think she meant he couldnt sing certain kinds of songs[perhaps he didnt want to],that still doesnt mean he couldnt sing, he certainly could,and he could entertain.
Sarah Makem, would have probably thought gus elen couldnt sing, but, he could, but only in a certain style.