[donquixote99]

Originally Posted by finnbow

I think the song you're thinking of was "Fresh Air" by Quicksilver Messenger Service.
https://www.youtube.com/watch?v=7ejj81Y2ZlM

Factoid - The estate of Randy California, Spirit's lead guitarist, sued Led Zeppelin for copying the guitar riff from his song Taurus (they used to tour together). It was a long, involved and precedent-setting legal battle concerning music copyrights.
https://en.wikipedia.org/wiki/Randy_...yright_dispute

Oh yeah, Quicksilver. Memory plays tricks.

I'm no expert on music rights but it sounds to me like Zep's big song drew on the Spirit song, though additional composing was done and the Zeppelin work is therefore different. Judging what's enough to make it infringement is not something I'd want to have to do. I recall three notes were enough to win the lawsuit against George Harrison....