Terry Kath’s soloing on 25 or 6 to 4 is absolutely amazing. It may the track that caught the ear of a guitarist - IIRC, Hendrix was his name.
There’s a documentary done by Terry Kath’s daughter - really interesting.
It’s somewhere out there in the interwebs but worth the search.
Same chord progression as Zep's "Babe, I'm Gonna Leave You".