A friend of mine has started playing and I will ask where she is getting her tunes from - though she plays piano and the transition between the two makes sense. It's a white note piano. I can play guitar and can play a keyboard up to a point and once the harp was explained (and how it was tuned and what the up and down levers do) then it makes sense so that I can play a tune on it. Not well but it makes sense. It is very like the inside of a piano!

Leeneia is right. If you can use chords just to give you the bass notes then there is a huge wealth of tunes in ABC format or similar (which is easily convertible) on sites like thesession.org

I have linked to the Kesh jig as an example. If you scroll down on many of the tunes you will find that someone has added chords. If you play octaves or octaves and fifths in your left hand to mirror the chords and pick the tune in your right hand you should have lots of material.