Score to all the op 32 Preludes
According to IMSLP, where I found this score, the piece is public domain in the US and Canada...I've forgotten where you are, though. 
Whilst you're there, spend a few happy days downloading IMSLP's treasures. There are reams upon reams of them. I must have a couple of Gigs of scores from them by now.... 
Thank you very much Luke. Does not look easy to me
Starting from Bar 6 (page 21) when the right hand motif starts, the right hand should be kept open for the B to B octave throughout I suppose. But, from what I hear from the recordings (and I have slowed them down on the editor), they seem to be playing two notes following the GF#GF#: a B and a C in quick succession (in the second run two B's, the third B and C and on the fourth B &D). However, the sheet has only one note instead (C on the first, B on the second, C on the third...). This is of course much easier, but I wonder if you can create the same effect
