Sonny and Cher were originally considered a "Folk Rock" band--remember that it was applied much earlier than the 70s--All the pop bands led by former folkies and anything with acoustic guitar and a backbeat fell under the rubric--

The Byrds, The Lovin' Spoonful, The Association, Barry Mcguire, all were called "Folk Rock" Dylan and The Band, of course, tend to be credited or blamed for originating the form, which is an absurd idea. Rock and Roll is really folk rock--and what about blues?

Folk Rock morphed into Psychedelic, and then to country rock, as evidenced by Bobert's list.

The marketing folks and the publicists touted Folk Rock as considered a sort of "fusion" music,that took your tired old hand-me-down folk music and making something new and exciting out of it--"The Kaleidoscope" and "It's a Beautiful Day" are a couple of bands that really did that--which is probably why most people have forgotten them--