Cited this photo review of 1970's D.C. Independence Day celebration in today's C&L Round-Up, but it seemed worthy of additional (& morbid) research. To wit, other than Pat Boone (Glad I checked on him; was fairly sure he was worm food.) & Jeannie C. Riley, every individual performer listed below is as dead as (if not actually deader than) a doornail.The Centurymen® are celebrating their 50th Anniv.; doubt if any who sang at the 1970 shindig are still at it. The Young Americans are still at it. As are The New (Really?) Christy Minstrels, founded in 1961 & still under the direction of their founder, Randy Sparks (Who knew?) who must have been at the gig.
Big question is how many of the "400,000 others" are still kicking?
Text (if you can read & if you can get past the WaPo paywall) of the event, via No More Mister Nice Blog.