I think all music is technically over-rated, though the actual meaning of that phrase becomes pretty hazy. Every musician's music will always be marketed by people trying to make money off the back of him, subsequently trying to hype him in an effort to 'sell' him. Not a true picture really. Even in the case of a purer, untouched form of music, possibly a local act or even bedroom guitarist. Word-of-mouth only consists of opinion of Mr A influencing a the more critical opinion of Mr B who bad mouths Mr A's judgement to angsty teenage Mr C who happens to love aforementioned group etc etc.. It is impossible to say whether something is musically over-rated or not. Due to the nature of music being subjective, all people can ever offer is opinion. Basically, this thread was destined to turn into a 'who do you dislike thread,' especially with the lack of thought anyone here can apply. However I propose for the time being that, regardless of how impossible it is to say, a band who's recent success is largely based around media hype as opposed to actual musical virtue would be, as previously mentioned (I know theres some contradiction in this) a group like Oasis or U2. Oh, and Chick Corea is awesome