I've musically been paying most attention to The 70's Supremes and other girl groups from the 70's-80's and surprised I haven't yet mentioned The Friends Of Distinction, another favorite group whose catalog on CD is long overdue and needs to be reissued. Their first two were released as a 2-on-1 CD, but there's at least three more that's never had a CD release.
Harry, Jessica, Floyd and Barbara - and I believe The Friends Of Distinction are still touring, not too long ago with at least one original member (Floyd Butler). I've read their music has been compared to the group the Fifth Dimension. The Friends first came out in 1969 with "Grazin In The Grass" and disbanded sometime in the mid 70's, until much later reforming with mostly new singers.