"but the performances were done during the early stages of their career, so there is no way to compare their later work. "
YEs, the early and later work are two different beasts and largely represent the transition from "rock and roll" created largely for the purpose of dancing as it became established in America in the 50's to "rock" and all its derivations, which is what became popular after the BEatles and though occasionally danceable, covers a much wider array of artistic purpose and intent.
Early and later BEatles are two different things and their transition is a microcosm of the transition that rock and pop music itself underwent during their tenure, FWIW.
Its also noteworthy that rock and roll had its roots in prior uniquely American music forms created and popularized largely by African Americans, prior to Elvis, in the middle 1950's. Rock and Roll music actually faded from popularity then in the late 50's after many of the big names of the time (Elvis, Chuck BErry, Little Richard, Buddy Holly + co) stopped performing for various reasons. The BEatles took this and presented it as a stylish British import fueled by their raw talent back to AMerica several years later and then introduced their own artistic variations.
Fascinating stuff!
