SURE, THE FAB Four’s diverse musical history has blurred over time into a miasma of nostalgia, highlighted by pop fare like “Hey Jude,” “All You Need Is Love” and “Strawberry Fields Forever.” But the Beatles could get as heavy as the Who, Cream and the rest of the 1960s acts for whom they paved the way. Consider John Lennon’s “Ticket to Ride,” a 1965 rocker that featured Ringo Starr’s heavy drum rhythms and a circular guitar riff performed by George Harrison on his Rickenbacker 360/12 and Lennon on his Fender Strat, all of it girded on the verses to Lennon’s low, droning guitar notes. Later that year, Paul McCartney plugged his bass into a fuzz box for Harrison’s Rubber Soul track “Think for Yourself” and turned it into the rattiest-sounding lead guitar.