News World The London rooftop where The Beatles played their final impromptu gig will be immortalised by a new museum dedicated to the band due to open next year. "The Beatles at 3 Savile Row" will give music fans the chance to explore the building where Let It Be was recorded, with the former headquarters of their record company Apple Corps Ltd to be converted into a shrine to the band. Formed in Liverpool in 1960, The Beatles sold more than 600 million records worldwide, capturing the cultural upheaval of the era, influencing generations of artists and creating a musical legacy that endures to this day. In 1969, John Lennon, Paul McCartney, George Harrison and Ringo Starr played what turned out to be their farewell gig, performing Get Back and a number of other songs before police arrived and told them to turn down the volume. "There are so many special memories within the walls, not to mention the rooftop," Sir Paul McCartney said in a statement on Monday.…