I tuned my guitar down to open D (D A D F# A D) last night and tried playing "Payday", by Mississippi John Hurt. This is an easy song, with NO chords, alternating bass all on open strings and a single note melody line, playable mostly on the first and second strings, with only my second and third fingers needed. It was easy and sounded very good. The open tuning has a certain ring to it.

What I need now is more simple songs like that to play. I need a repertoire.