In 1952 I heard "The Old Piper" sung and played by Fracis McPeake ("Old Francie," as introduced by his sons). We were all part of a huge folklore extravaganza put on by the English Folk Song & Dance Society (Cecil Sharp House) in the Royal Albert Hall in London. The McPeakes came to our house for a meal, and sang into our microphones for us. Young Francie said he couldn't possibly sing the song as he hadn't the "Nyyyyanh," for it as his Da had! I'm sure he sings it now that Old Francie is gone West.

Anyway- what your originl memory about the song, Paddy, is that the song's first vs ends,"...and this is all the tune that he could play."
He also goes down to Hell in the end, still playing the song. Sure you weren't talking about a piper instead of a fiddler?