It would seem that MTV have remembered what their (previously-orphaned) acronym stands for, turning their attention away from mouth-breathing reality-show nonsense, and on to music, of all things. With the announcement of the Shepard Fairey-directed Rebel Music calling attention to youth subcultures around the world and the transcendent tunes that soundtrack their lives, the idea hits that the floundering music-channel grandfather has either finally realised the error of its ways and is earnestly trying for relevance, or has just been subject to the law of diminishing returns. Either way, the cable & satellite success story of the 1980s wobbles its way to Cork…