Good covers are few and far between. They usually consist of Band A reinterpreting (read butchering) a much loved arrangement of Band B. Or even worse, a faithful emulation that comes off as bad karaoke. When Radiohead are the band you’re covering the margin for error becomes that much smaller, Gnarls Barkley thankfully, are up to the task.
Picking the most accessible cut off “In Rainbows” is a good start, having the soulful pipes of Cee-Lo front and center probably doesn’t hurt either. I must admit, I like it.
Regardless of what you think, I’m of the opinion that bad covers are better than bad remixes, if only because bands can at least play their own instruments. I wonder whether Prince would approve of this?