O.o why is this suspected to be anyone's promotional videos?
What else would they be? They have previously unheard music as the soundtrack and may fit some artist's imagery. Also, it's listed under the music section on Youtube so must belong to an artist. Also, why is the description so, err, nondescript?
Just playing, love Britney and everything she does
Maybe it's Christina, if it is then Christina has blown me out of the water. Maybe some lesser known artist though.
Amazing sound whoever made it though!