It is a widely held belief that covers of popular songs are just, well, a bit crap. An artist producing their own version of a well-loved successful song is usually a recipe for disaster and, more often than not, leads to unfavourable comparisons between the classic and their sub-par effort.
However, there is a sub-section of covers that deserve everybody's respect: those which are so popular, they are able to supersede the original. This usually occurs in one of two ways: taking either an obscure song that very few people have heard before, or choosing an old song that has fallen out of popularity over the years.
Certain notable covers have managed to dramatically alter the genre of the original and, as well as introducing them to a whole new audience, often them given them an entirely new meaning. In some cases, the original purpose of the song is the complete opposite of the cover's.
There are even some examples of a cover becoming so successful that they have helped to launch the careers of some of the greatest musicians of all time. Ever heard of Elvis Presley or The Beatles? You might not have not they not found some coat-tails to ride on.