BBC Radio 1 Covers

In the strictest sense, a cover is a remix, lifting the lyrics and major instrumentals at minimum. As a category of music, it highlights the musical talents of the artist by referencing a ubiquitous piece to act as a benchmark of vocal talent, originality in performance, etc.  

BBC 1 Live Lounge has a tradition of having musical guests cover the hit song of the day. Some are incredibly similar to the original, leveraging the in the nuances of performance to make it unique. 

The Kooks - Pumped up Kicks by Foster the People
uploaded by MELOMANODAV 

Others, still working inside of cover category, are notably different in tone, emotion, narrative, etc.; all the soft interpretations that make art enjoyable.  

The Noisettes - When You Were Young by the Killers

uploaded by pheonix music and movies

And still, the cover can be extended further, keeping only the barest musical forms like written chord progression and melody. 

Lady Gaga - Viva la Vida by Coldplay

uploaded by Little Fame Monster

So, at what point has a cover moved beyond the referential? At some point, it sounds like the only requirement for a performance to be a cover is the citation.  

And what do we, as an audience, want out of a cover anyways?

PS. BBC1 Live Lounge still does this, and finally post them on their official channel, but all of the videos cited here pre-date the official channel. Anyone care to count all the people who could have these taken down and why they why it benefits them to keep it up?