Let me add emphasis to this quote by Richard Dyer-Bennett in Don's P.S. — articulation, good diction, matters a great deal. Make sure every word you sing, whatever the song, is clear to the audience. As a record reviewer, I have always been very down on the self-indulgent 'singing into one's own navel' kind of performance that some think it clever to indulge in. It isn't. I am sure all the professional singers on this forum will support me in this.

Otherwise, I agree with every word Don wrote. He is American, I am English, but the same principles obtain. You need 2 repertoires, really — one for specialist audiences who would like to hear something new, and one for the general public who like to hear the familiar, and feel secure with it. This is no sort of value judgment, just a statement of the situation. Both sorts of audience are important.

Best of fortune in your endeavours. Folksinging to an audience can be most rewarding at all sorts of different levels.