In looking round the web, I see that Alan Ross has been incorrectly claiming that his father also owned copyright on the tune, as the first to record it, for example Copyright in a tune belongs to whoever records it in a fixed form and from that moment it cant be used without permission. This is not justifiable. That copyright either belongs to its composer, or, if the tune is traditional, copyright may exist in a particular trnscription of that tune.

From the PRS website:

Copyright law states that if you write down a traditional song, this transcription becomes a copyright work. The copyright lies in the transcription and not in the traditional song.

This means the transcription is copyright. It may not be copied, reproduced, published, publicly performed or adapted unless permission is obtained from the transcriber. However, this does not prevent people from transcribing from the same source. By doing this they create their own copyright - even if their transcription is note for note the same as an existing transcription.