Recorded during the same 1965 session as “Yesterday,” “I’m Down” is in my opinion, the Beatles’ best flat-out rocker and the best B-side of all-time.  Yes, “Revolution” and “Helter Skelter” may sound “heavier,” but “I’m Down” is much more ferocious in terms of speed and attitude.  McCartney tries to out “Little Richard” Little Richard here and he comes really damn close to achieving his goal.  A phenomenal tune that again … shockingly … was merely the B-side to “Help” and wasn’t included on a proper album until the late 1970s, when it appeared on their “Rock n’ Roll Music” compilation.