Has there ever been an album devoted to one song by different singers?

I know it sounds gimmicky but I think it might be interesting to hear the variety of interpretations and sounds that can come from one song. I was just on YouTube and did a search for Danny Boy. There is a large range of different types of people singing it, including Charlotte Church, Andy Williams, Judith Durham and Harry Belafonte. I also wonder if anyone has ever determined which song has been recorded by the most people.