The Beatles never met a genre they didn't make their own, incorporating everything from raga to chamber pop to vaudeville during their revolutionary career. Still, when most people think of the Fab Four's vast catalog, "heavy" is probably not the first descriptor that comes to mind — but don't think for a second that rock's greatest shapeshifters couldn't bring the heat.
From their early days as Liverpool's premier club band to their godlike status in the late '60s, the Beatles delighted in destroying and rewriting the pop music playbook at their whim. They worshipped at the altars of Little Richard and Chuck Berry as kids and could whip audiences into a frenzy with their breathless rock 'n' roll freak-outs.
Source: ultimateclassicrock.com