As a baseline I favour the writer as being the best interpreter of his/her own words. Even more so when the words come from a perspective that is so singular, so personal and from such an idiosyncratic person. We are not talking Yip Harburg or Cole Porter here. This does not mean I close my ears and mind to the versions of others. The reference to J. Warnes is timely. I will give Holly Cole a listen. I don't mean to sound dismissive, but again, to me, the limits of the performers voice, the lack of polish, the lack of training all contribute to what the performer is. Sorry about this "warts and all" approach, but I usually don't think that what we call in French a "chanson à texte" is in better hands when a more musical, better trained singer performs it. I find it usually loses something in the process. It sometimes work, but not often. I'm just as happy if the likes of Céline Dion never mangles a song with lyrics that go beyond the present equivalent of "moon" and "June". Believability is the one ingredient I can't do without. When the writing is so personal, the words coming out the mouth of someone else feels somewhat contrived to me. Not an absolute, just my own observation/prejudice.