I keep looking at the thread title and puzzling over exactly what is meant by a "tribute album"

There are lots of worthy names here which in many cases, I suspect, simply represent individuals' favourite artists.

The OP wrote:

In your opinion,who deserves a tribute album dedicated to their contribution to music?

Which I find delightfully vague. In particular, how would such an album differ from a "best of ..." compilation.

I think to earn a tribute, an artist has to go beyond simply being popular but has to have made a significant contribution to music - in Mudcat's case, folk and blues - however you may define that.