I am one incident closer to having an imaginary best friend named Wilson because I cannot find what I am hearing over and over and over again in my head. As the title suggests, I heard a Chopin (or was it Rachmaninov?) composition with both left and right hands playing octaves starting on C# then C (half-step down), then up to F# and then a half-step down to F and this repeated up the keyboard.... What is it? I am going mad...I've been listening to all my CDs and still cannot come up with it. Thanks, -Wilson's friend.