ARRGHHH! Sorry! All these helpful people. Go easy on me. I am a 50 year old learner. I ain't got much time left to learn theory or how to read SN or Tab quickly.   I can read treble clef standard notation enough to at least place chords with notes over the lyrics.

I have just discovered through another mudcat thread that my idol, Odetta, used open D tuning and a capo. And that she only used a few chords in most of her playing. I have searched and discovered what open D is.

I am a bit worried about retuning the guitar. What happens to the songs I already know how to play and sing?