Great program; the only problem I have with the documentary is that they were really stretching the definition of "rock & roll." Some of the stuff played definitely fits other categories like R&B and/or Soul rather than Rock.
Some of the other stuff that nominally fits in the Rock category is sappy, syrupy stuff that nearly made me puke in the 1970s (Captain & Tennille? Really? Gack.). Nearly 50 years later, I find that I don't mind it quite so much. Even certain entries which belong in the Disco category don't make me want to go out and break windows downtown like they used to.
Even so, I've got it playing via an online SDR on my desk at work right now. . . .
It was a good program back in the day. They originally delivered it on LP records, if memory serves. Then reel tape. Then CD. It was a popular program for pop and rock stations to play during Memorial Day weekend, or other three day weekends. One thing I remember was the show segments always had a teaser to keep you tuned for the next segment after the commercial break. Expertly done radio overall. Sorry I missed it on WTWW.