I grew up when there were still Belafonte Calypso, Weaver, and The Kingston Trio albums stacked by the record player in my parents house. It was the music my parents listened to. To me they all looked glossy and posed and clean-cut (except for Bob Dylan. I don't know why I thought that or cared - but this was when buying an album meant buying a record sleeve that had a poster on one side and a book of text on the back. You could see the band and then read about how and why they had formed and written and published and toured.
Read all about it here.
Or, take a look at this TV appearance:
Sure they had their critics, and their have been many official incantations of the same trio with new members, in fact there may be one coming to your town soon. Here's a final look at another page in the book - they were sought by many advertisers...