"Stairway To Heaven" Plagarism court case

zep is unquestionably great, but has a long history of putting their names on other folks' tunes (or traditional songs) and, to my knowledge, already paid off for "dazed and confused" and "bring it on home." they also had to change the credit on "baby i'm going to leave you" to the actual writer, anne bredon, some 20 years later. not sure of the legal disposition of "lemon song" or "whole lotta love," but they're straight howling wolf/willie dixon cops. as for the intro to "stairway," i dont doubt that zep heard the spirit song first, but it's much more ambiguous as to whether zep crossed the line from "influence" to outright infringment. it's probably bad policy to draw the line too rigidly--almost everybody borrows elements from other songs, and in this specific case (as oppossed to :my sweet lord") the overall concepts of the songs  were sufficiently different to give this one to zep.

One can’t help wondering why Led Zeppelin never went after the band that recorded the album, Hairway to Steven. Seems like a lawsuit made to order.

The weird thing about the outright Zep rip-offs is that Jimmy Page generally didn't bother to change the lyrics very much. When you borrow the chords and melody, it might be influence, but when you do that to Bert Jansch's Black Water Side and call your song Black Mountain Side, you're kinda begging for the lawsuit.

I don't think that Stairway falls into that category (and - were it up to me - I wouldn't award Spirit/Randy California's estate any money) but Page has poisoned the well so many times that he might lose this one on principle.

Please note , on copy right infringements  there are just so many years 
Not sure  how many,and what %  of  the song was copied ?

It's a small portion of the song overall.  It's accompanimental and not melodic.  There shouldn't be much of a case here IMO but look what happened with the Robin Thicke/Marvin Gaye suit--those people on the jury must have ignored every instruction pertaining to the particulars of copyright law.  I'd say there was less ground for a suit there than in the the Stairway case.  Anyway, it's a shame that a great talent like Randy California will be known better for this rather than for all the great guitar parts he laid down over the years.  The first four Spirit albums contain a lot of fine material.