S-WC outlined all sorts of reasons why cover versions are recorded. As he mentioned, sometimes it can be for a tribute album. From wiki:-
The Smiths Is Dead is a tribute album to the 1980s’ English alternative rock band The Smiths, released in 1996. It was compiled by the French cultural magazine Les Inrockuptibles and released to celebrate the 10th anniversary of 1986’s The Queen Is Dead. The album was released at the height of the Britpop phenomenon and contained covers by many popular Britpop acts such as The Boo Radleys, Supergrass, Bis and Placebo.
It’s very much a mixed bag and I think it’s accurate to say that none of the covers improve at all on the originals, but that would have been a near impossibility to begin with. The other biggest problems are that too many of the tracks fail to digress all that much from how The Smiths themselves recorded the songs or that the band asked to do the cover do so in a way that even Morrissey’s backing band would have been embarassed by the efforts. However, an honourable mention must go to Boo Radleys for what is a hugely different take on the title track…..one that too me many years to really appreciate but nowadays is the only one I have on the i-pod :-
mp3 : Boo Radleys – The Queen Is Dead
mp3 : The High Llamas – Frankly, Mr. Shankly
mp3 : The Trash Can Sinatras – I Know It’s Over
mp3 : Billy Bragg – Never Had No One Ever
mp3 : The Frank & Walters – Cemetry Gates
mp3 : Placebo – Bigmouth Strikes Again
mp3 : Bis – The Boy with the Thorn in His Side
mp3 : Therapy? – Vicar in a Tutu
mp3 : The Divine Comedy – There Is a Light That Never Goes Out
mp3 : Supergrass – Some Girls Are Bigger Than Others
Enjoy.
THE NEW VINYL VILLAIN 