I was listening to a ~2015 Jimmy Page interview when my ears perked up as he talked about a previously unreleased tune recorded around the time of the Led Zeppelin II album. He said the name was "La La". It was recovered around the time of the interview.
I had it in my collection already. It's in the II deluxe tracks if you have downloaded it or purchased in the past 8 years. I just had no context of it's meaning or significance. Finally gave it a second listen and it's a brilliant tune. Everything groovy I like to envision through sound about the late 1960s.
There was another recently recovered song (2019) by the Rolling Stones w/ Jimmy Page in it from the early 70s. Recall Jimmy Page and John Paul Jones were seasoned "session musicians" throughout the 1960s. Not sure if Page is sitting in by request for the Stones or exclusively featured.
Always interesting what shows up 50 years later!