[Andy Howell]

I almost certainly have!

Steve Roud's comprehensive history of English traditional music has a couple of interesting sections on melodies and tunes. He quotes an academic study (from the US) which set out to categorise and analyse traditional tunes, those that you often find in English, Scottish, Irish and US trad music. Apparently, they could group tunes into just 12 groups!

Adding riffs and rythmns complicates things a bit but you get the drift.

Copywrite obsession is, I suspect,something developed by lawyers!