"Back in the 60's and 70's "folk music" was frequently in the charts and thus got plenty of exposure in the UK both on radio and TV"

I agree completely Iains. I knew at, least something, about folk music before I got involved in it due to the different types of exposure on the TV. Most Saturday night variety shows would include spots from non-mainstream pop. I also had an inkling about some World genres such as Flamenco, Latin American, Calypso. Equally, I knew what jazz was and could distinguish modern from trad jazz. I knew of Oscar Peterson, The Dudley Moore Trio, Buddy Rich, Kenny Ball, Acker Bilk and many more.

It's sad that this doesn't happen these days - even the mainstream pop is no longer authentic.