Rod Stewart some years ago released a CD with 'Will ye go lassie go' as one of the tracks, he also claimed to have composed the song. The McPeak family (Belfast) claimed copyright on the song as their grandfather had composed the ballad and had recorded it (before Rod Stewart was born . . must have been in the 1800's)he was forced to recall all the CD's or face a hefty court battle, they were all recalled. I'm sure Rod Stewart was not the first person to attempt this!
Eoin