Hi Martin,
It depends on where you are as to the stringency of the copyright laws, and I honestly don't know the details of any of them, though they can be found online by searching.
If you sell arrangements like this, you have to pay royalities to the copyright holder. If you make your own arrangement for your own personal use, you don't have to do anything. My understanding of US copyright law from past research is that if you have done the arrangement from scratch (no cheating using a lead sheet or anything like that) and are not charging anything for it, you can share it for free. However, if you used a printed lead sheet from a copyright copy to add in any of the notes, you have to pay royalties. How's that for convoluted?
John Denver did know how to write some memorable tunes, didn't he? This was one of the first songs I learned to play on guitar
ttfn,
Sherry