Nobuo Uematsu openly admits that he gets inspiration from other songs. He said it in an interview I saw on the Advent Childeren DVD. He got inspiration for the Sepiroth theme from Jimi Hendrix's song Purple Haze.

Regardless, Let My Love Open the Door is AWESOME!!

I heard that song in some movie when I was a kid--I know this song but I don't remember the movie!  And no.  I don't think FF copied this song.  But imagine if they did!  It would destroy Square.  Remember how that song "Land Down Under" got the group, Men At Work, in trouble?  And all they did was use two seconds of an old song (Cooka Burrow sits in the old gumtree--I know I spelled it wrong.).  Bury this thread or risk never playing another Square Enix game again!

while its true , inspiration =/= copy.

i don't think those two sound anything alike , purple haze and one winged angel.

I always thought One Winged Angel was from Rite of Spring:

(starting at ~3:02)

Good for Nobuo that Pete won't notice. He's almost deaf.

it's an arpeggio like others have said.  That's all it is.

Some the Preludes have things going on it besides the arpegio.. like FFX's... and I think FF7's? and probably others.

But it's more of a choice to use an arpegio as the Final Fantasy Prelude that makes makes it unique, than the actual prelude itself.

The beginnings sound the same but that's about it. 

talking about S-E music inspirations...