While led Zeppelin certainly “borrowed” more than a few songs, this is not one of them. The spirit song has not melody. Only the first 2 chords are played exactly the same. Many songs revolve around a single chord with a descending bass line, both in minor and major keys. This case was a loser from the start. You can only copywrite melody and lyric. Pop and rock is basically the same 20 odd chords, with various different melodies and lyrics to those same chords.
Pop and rock is basically the same 20 odd chords
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LOL.
So true. The 4 or 5 chords they know in 4 keys.
The bluegrass guys know better ... 3 chords and the truth :-)