I'm not very well-versed in punk rock, but even with my limited familiarity, I was still amazed by this NYT article on what could be called the first punk band. A group of black guys in Detroit basically cuts the first punk record two years before anyone else, but it never gets a major label release (partly because the band was named "Death," partly because they were black) and almost everyone forgets they existed. They never tell their kids about their days as Death, but one of their sons hears a song at a party in San Francisco decades later and recognizes his dad's voice. Now, it's being released by an indie label, and many people acknowledge it as the earliest example of proto-punk.
Listening to sample track Politicians in My Eyes, it does indeed sound halfway between classic rock and punk. It's good, and very impressive for 1974.