Francis O'Neill prints this as a march in Waifs and Strays of Gaelic Melody (1922), listing himself as the source, and includes a verse:

Gay Robin was a piper young, and many an air he played and sung,
But sweetest far the love fraught lay, 'Over the Hills and Far Away.'

What's this Sharpes' Rifles? I know what a Sharp's Repeating Rifle is.

Read up on the show, Napoleonic era, eh?