STAIRWAY TO [LITIGATION] HEAVEN

Some of you have no doubt heard about the current court case involving a claim of copyright infringement against Led Zeppelin for the opening to their big hit "Stairway to Heaven."  You can read about the case here.  That link also lets you listen to the opening of Stairway to Heaven and to the opening of Taurus, written and performed by Spirit whose members brought the lawsuit.  To my ear, they are obviously similar, but at face value would not rise to the level of plagiarism IMHO.  However, I am no professional in this area.  This YouTube video provides an in depth analysis without an opinion:

Here is TJR's follow up analysis that gives his opinion:

So - my amateur opinion?  I don't think that you can make a copyright claim on a chord progression.  There are literally thousands of songs with virtually the same progressions but are clearly different songs.  Taurus is an instrumental that goes a completely different direction after the opening riff, and Stairway to Heaven does the same.  Did Page copy the gist of the progression?  Maybe, but to me that is no plagiarism.