The host of this show was a comedian whose first name was Robert, but I can't think of his last name. It was something like Klein or Stein, maybe with another syllable at the end. As with Jack Carter serving as substitute host on the Joey Bishop Show the previous New Year's Eve (see message under 1968), I didn't think he was very funny. I think he may have been a guest host for that week (with the series having a different guest host every week), rather than a permanent host.
Another guest that night was Cass Elliott, Mama Cass of the Mamas and Papas, who died at too young an age in 1974. At the end of the show, Neil and Cass snuck back on stage (or appeared to sneak back on stage) and picked Robert up and carried him off, as if they knew he was not being very entertaining.
One of my favorite groups from that time period, the Creedence Clearwater Revival, made one of their rare TV appearances on that show.
Because my overriding memory of that show was of Neil and Cass carrying the host off at the end, I had forgotten what Neil sang. Also, his Ed Sullivan appearance of the previous night had still been fresh on my mind. As a result of a recent video of this appearance recently being released, I now know that he sang "Holly Holy", his then-current hit single, and "Both Sides Now" during that appearance.
-- Regina Litman