My brother was a music major and is in a band. His opinion was that everything's been written and it's all just "sampling" now. For example, Blues Traveler's "Hook" is deliberately based on the progression in Pachelbel's "Canon in D" and it's that very melody that is the hook in "Hook".The baseline of the chord progression in Taurus and Stairway is formulaic and fundamental and very old, that they both used it is a coincidence. It's entirely possible that Page heard it in Taurus and doesn't remember it but the burden of proof on the origin of the idea is on the plaintiff. In both cases, I think it can be said that they both got it from a prior source and that source is unknown.They took a shot, they lost.
It's not just happenstance in my opinion. Those two bands played shows together, and at the time when they did, Spirit definitely would've played that song at the show. Jimmy Page can't truthfully say that he never heard that particular song before writing Stairway to Heaven. I can't blame him for fighting it out in court to keep his money. I'd do the same thing. But I'm pretty sure that if he would've lost and had to pay anything, in his own mind (cuz he'd never admit such a theft to a living soul) he wouldn't have been calling it a total injustice.I'm just kinda surprised it took THIS LONG to bring it to court. Like I said, even as a kid I kinda thought it was probably more than coincidental that those songs sounded so alike. They couldn't have NOT heard the same thing until just recently. Maybe it took them this long to get enough money pooled up to afford to take it to court. I guess if they would've gone after it on the cheap, either Led Zeppelins attournies would've settled for 2% of the potential award they could've gotten for winning, or they would've simply gone ahead to trial and outspent them with experts to back their defense. So, yeah, they took a shot and lost, but I can't see the surviving members of Spirit bothering with such an expensive task in the first place unless they knew they were right. Sucks for them. They should've been more famous I guess.