Led Zeppelin was pretty notorious for borrowing riffs and melodies. Led Zeppelins first US tour was opening for Spirit, so...

Over the years, the writer of the ripped off song was magnanimous about the whole thing. Interesting blog about it below. I guess now that he is gone, the family has decided to get him some recognition and some cash in their pocket.

Led Zeppelin: Plagiarism? ?Stairway to Heaven? | Turn Me On, Dead Man

I don't like Led Zeppelin for a number of reasons, including the fact they stole Dazed And Confused from another artist. Lots of artists pilfer music. It's really common. But Led Zeppelin became notorious for it. There's lots of information outs there on it, but they're such a popular band that it doesn't seem to mar their reputation.

I suppose it doesn't help that I absolutely despise classic rock. Ugh.