Verified answer

I'm pretty sure it is the part when the Will, Cutler Beckett, and Davy Jones meet with Jack Sparrow, Elizabeth & Barbossa on the island - they show it and it is like an electric guitar piece - I read somewhere (of course now I can't find the link as to where I read it...) ;0( But I read he played the electric guitar in it, and I think thats the only part I heard it in (at least that I could tell)

Great movie, BTW!!!

I haven't verified this, but someone told me that it's a tune that Keith Richards wrote for the movie.

I'd imagine it's not a Rolling Stones song, as that would kind of take away from the whole "pirate" aura for most peope ....

Yo ho yo ho a pirate's life for me!