TWENTY-FIVE YEARS on from their demise, The Beatles continue to exercise a hypnotic spell as the ur-myth of modernist pop culture. As befits the group who epitomised the youth principle in Western society, their early records retain an innocence and first-time energy which still makes them fresh. The conduits of what later became a significantly new youth perception, they can stand up to the most rigorous analysis – like Ian MacDonald's great Revolution In The Head – and come out sounding even better.