From the TV show Maude on the episode Phillip's Birthday Party, at the 2:20 mark the band starts playing The Ocean.
This was originally aired 10/31/77 on CBS. I am not sure if Peter Grant or Led Zeppelin were aware of this.
in case clip does not appear, it is listed on you tube under : goto 2:20
Maude - Phillip's Birthday Party (Season 6, Episode 6) 2/2