The Led Zeppelin verdict is in, and its an acquittal. A victory for common sense, to me. First, you can't copyright a part of chord progression — if you could, there would only be, like, 20 songs in the world.

More relevant, though, is what I advised the Led Zeppelin team to focus on: that the descending line underneath an arpeggiated A minor chord goes back way before Spirit's "Taurus" in 1968 — a string of 60s hits used it, including "Music To Watch Girls By" and "Chim Chimminey". The legal maneuver is not to try to prove that Stairway to Heaven is different from Spirit, but to show that both songs are borrowing from a musical motif that goes back at least to the time of Bach.

This is a switch from the way lawyers used to defend copyright claims. I worked for CBS when Billy Joel and Michael Jackson were sued, respectively, for "We Didn't Start the Fire" and "Billy Jean." In both cases, previously unknown songwriters who had never written anything before, claimed that these brilliant songwriters stole their songs. How likely is that? The defense tried to prove differences and won, but they were tough trials and there were many other cases defended with a similar strategy that lost (such as the My Sweet Lord/He's So Fine case). There are lots of songs that sound alike, but hey, there are only 12 notes.

Daniel Levitin