In the first message of this thread, Santa suggests that
'to look at the roots of a song... could even be a bad thing, in restricting "creativity". '

How can widening your knowledge restrict anything?
If anything, learning a song from a collection in a book is going to result in a more creative performance that learning it from someone else's later interpretation of it.

There is nothing wrong in having your singing style informed by listening to traditional 'source' singers. That's emphatically not the same as imitation.

Surely it's valuable to see or hear as many versions as possible of a song, at least some of the time in order to appreciate the whole process and that there is no "definitive" version of anything. After that you may choose to make your interpretation similar to someone else's, but at least you know you are doing that.
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I have a pet peeve about people who get up in a folk club and introduce a traditional song with "this is a Martin Carthy Song" or whatever. All that tells me is that the singer is too lazy to do their research properly. Singers like MC will look at many versions of a traditional song and pick the one that best suits their voice, temperament of understanding of the song. The result may not be the best for another singer, who could do the same thing and maybe come up with a totally different tune, arrangement or performing style.

If you don't go back to the source you'll never know what you missed!

Anahata