The Young Generation were a troupe of young British women and men who danced and sang on various television variety shows in the late 1960s and 19790s, one of numerous groups of this sort. This particular gang appeared on shows hosted by the likes of Rolf Harris, Lulu, Vera Lynn, and Engelbert Humperdinck, and even had their own show for a time. I'm not sure if there's an exact American equivalent, but they are sort of a cross between a co-ed version of Dean Martin's Golddiggers and the Ray Charles Singers.
I'm not sure if any of them went on to great fame; groups of this sort seemed to function like some kind of glamorous choreographed ant colony, there to glorify the queen bee program host or guest stars, and provide some eye candy between the other acts in a one-hour program. Not to say that they don't have talent, just that their ability to blend and function as a unit is more important in this context than their individuality (although I'm sure regular viewers had their favorites).
I grew up watching, and loving, variety shows on TV, and they made an indelible impression on me. In fact, I often try to imagine how rock songs might sound with slick variety-show arrangements, and big productions. (That's partly why I like that theatre-organ arrangement of "My Life" that starts off Do Your Own Thing.)
I considered using the cover of the album on which this song appears as a basis for the cover art for Do Your Own Thing, but felt it was a little too exciting.