For a band who put the mind-altering mayhem of psychedelic music on the map, the entrance to Pink Floyd’s first international retrospective seems surprisingly literal. But the Victoria and Albert Museum’s eagerly awaited exhibition celebrating one of the most influential and successful groups of our times defiantly begins in the Bedford van that Syd Barrett, Nick Mason, Roger Waters and Richard Wright took on their very first tour in the 1960s. Those early days of Pink Floyd might sound rather prosaic. But just a decade later they released a multimillion-selling concept album, Animals. On...