About six weeks have passed since this thread started, and I've had time to do more work and learn something. I learned that I had used the wrong when I said 'alto clef.' The old clef in the 1805 book, the one that looks like a ladder, is called the Counter clef or C clef.

I suspect it was sung an octave lower than written.

Yesterday friends came over to have dinner and play Irish music for St Patrick's Day, and I passed the book around. Everybody was quite interested to see the old print and the archaic notation, and I was pleased.

I have now noted 32 songs from the book in MIDI form. Now what do I do with them?