[deleted] I think the insert reads like a load of old bollocks.
It is just one (of many) artifact to show that at the time a lot of people were talking about progressive in the same terms that Monostereo is above. It was not unusual. It’s an equally common interpretation.
Then again, a lot of people talked about punk as an attitude rather than a genre when it emerged, when in hindsight it was clearly a definable genre.