Some acts tried to copy their blend of vocals. The Chartbusters came close, and although they got some radio airplay, they came nowhere near to busting any charts.
She's the One--The Chartbusters (1964)
They never copied the harmonies, but “No Matter What” by Badfinger sounded “Beatles-ish” and of course “Lies” by the Kinckerbockers had the Lennon sound down.