purchase [Velvet Underground ]
The second group of 10 albums I owned included Janis Ian's '68 record, <The Secret Life of J. Eddy Fink> and the Velvet Underground's '69 <The Velvet Underground>.
At that time I had a mentor who directed my music selections and was ahead of his time - he also turned me on to Hendrix at about this time ('69)
I was certainly aware that these musicians were outside the mainstream (that would have been the first 10 albums I bought: Sgt Peppers, Between the Buttons, Smokey Robinson, Simon and Garfunkle..).
To me, the Velvet Underground had something meaningful to say - something beyond "corn flakes floating in a bowl" - lyrics that gave pause, music that made you sit up and listen. Something like what Elvis Costello had to say 20 years later.
It seems like I was listening to "proto-punk" without realizing it. Of course, that nomenclature only came about after the fact. Back then, it was a reaction to main-stream rock.
The general perception of Punk is <hard driving>, but I think that isn't a given: take a listen to this anti-most and see if it fits the "proto-punk" genre.