I might as well put my two cents worth in. I admit, I have sung other peoples' songs differently from the way they wrote them. Sometimes it was accidental (I had sung it so long and so often that it had evolved), and occasionally on purpose. But I admit I feel both ways about it. Consider Nanci Griffith's wonderful rendition of "From a Distance" (I know she didn't write it). A year or two later Bette Midler came up with a version that was a direct steal of Nanci's, right down to the tiniest detail (except that Nanci's voice was much sweeter). That really irked me! Ian Tyson wrote "Some Day Soon", a perfectly fine song as is. Judy Collins recorded it and for some reason felt compelled to change the tune. Ever since then, everyone that has recorded it has done it as Judy did it... not because that way is better (it isn't), but because they learned it from her record, or from a third-hand copier. They obviously made no attempt to find out the true origin of the song. I really let things like that bother me. So you can see, I feel strongly both ways! I guess what really matters is that when you sing someone's song, you give credit to the composer (and let the audience know if you have added the second verse), and by all means remember to pay royalties if you record it.