Led Zeppelin persuaded a US appeals court to reinstate a jury verdict that it did not steal the opening guitar riff for "Stairway to Heaven" from an obscure song written four years earlier.

In a 9-2 decision, the 9th US Circuit Court of Appeals in San Francisco said Led Zeppelin lead singer Robert Plant's and guitarist Jimmy Page's 1971 rock anthem did not infringe "Taurus," a song written by guitarist Randy Wolfe of the band Spirit.

The case has been among the music industry's most closely watched copyright cases, potentially exposing Plant and Page to millions of dollars of damages.

Wolfe, who performed as Randy California, drowned in 1997, and the case was brought by a trustee for his estate.

Lawyers for the trustee and Led Zeppelin did not immediately respond to requests for comment.

The trustee had argued that "Stairway" and "Taurus" had similar chord progressions, and that Page may have written "Stairway" after hearing "Taurus" while Led Zeppelin and Spirit were touring together.

In the June 2016 jury verdict, jurors found that while Plant and Page had access to "Taurus," its riff was not intrinsically similar to the opening of "Stairway."

Stairway To Heaven

There's a lady who's sure all that glitters is gold

And she's buying a stairway to heaven

When she gets there she knows, if the stores are all closed

With a word she can get what she came for

And she's buying a stairway to heaven

There's a sign on the wall but she wants to be sure

'Cause you know, sometimes words have two meanings

In the tree by the brook there's a songbird who sings

Sometimes all of our thoughts are misgiven

It makes me wonder It makes me wonder

There's a feeling I get when I look to the west

And my spirit is crying for leaving In my thoughts

I have seen rings of smoke through the trees

And the voices of those who stand looking

It makes me wonder It really makes me wonder

And it's whispered that soon, if we all call the tune

Then the piper will lead us to reason

And a new day will dawn for those who stand long

And the forest will echo with laughter

If there's a bustle in your hedgerow

Don't be alarmed now

It's just a spring clean for the may queen

Yes, there are two paths you can go by

But in the long run

There's still time to change the road you're on

And it makes me wonder

Your head is humming and it won't go

In case you don't know

The piper's calling you to join him

Dear lady, can you hear the wind blow

And did you know

Your stairway lies on the whispering wind

And as we wind on down the road

Our shadows taller than our souls

There walks a lady we all know

Who shines white light and wants to show

How everything still turns to gold

And if you listen very hard

The tune will come to you, at last

When all are one and one is all, yeah

To be a rock and not to roll

And she's buying a stairway to heaven