Here are some tunes by Carolan, the celebrated Irish harper and composer (1670-1738), in music notation.
I have no pretence to scholarship. Some are taken from the web, some have been set up by me.
There are other tunes to be found on the web. Some are in 'abc' format (one such file; read about abc) and some are sound files (a site with midi files of Carolan tunes).