One oddity is that it's the complete eight minutes of the number performed on the Tony broadcast. It includes several minutes not on the cast album, basically the part where the cast goes into parodies of other musicals. Another oddity is that this is the title number, a big showstopping extravaganza -- and the song isn't performed by the star of the show. In fact, it's not even performed by the main co-star. Rather, it's a minor character who gets to sing it.
Applause is based on the classic movie, All About Eve. It starred Lauren Bacall as Margo Channing, the Broadway star who is surreptitiously backstabbed by her assistant Eve Harrington, played by Penny Fuller. But the big title song is is sung by a theater gypsy who's the subplot of the show. And that's the other semi-oddity, since this young girl five years later would be the star of her own TV series, One Day at a Time. If you thought Bonnie Franklin was perky in that as the mother, she runs circles around "perky" here. She actually has another fun song in the show, "She's No Longer a Gypsy," and got a Tony nomination as best featured actress. However she lost out to Melba Moore in a star-making role for Purlie.
The score to Applause was written by Charles Strouse and Lee Adams. Together, they wrote the classic Bye Bye Birdie. And with Martin Charnin, Strouse (who did the music) wrote Annie.
One note: there's a lyric change for this television performance. Near the end, as the song builds to its final crescendo, the chorus sings, "Why do we live this crazy life?" On the cast album, though, what they sing is, "Why do we work our asses off?" So, in 1970, apparently, it was okay to show what appears to be bare asses in the scene (though I suspect are flesh-color covered), just not okay to say the word itself.
You can skip the first minute of this video, since it's just the introduction of the broadcast. Though it's sort of fun seeing the names of the people appearing. It's an impressive list. You might even want to give it some Applause.