if what they start with is fantastic to begin with. The Beatles only 'progressed' because they got onto LSD, less a conscious musical decision and more an artefact of copious tripping. It bugs me a bit when bands get criticised for their lack of it ...maybe they don't need to? Look at Arctic Monkeys' Humbug, crap album. It's just an easy target that music journalists like to aim at so they have something to whinge about.