I can just about get my head around debussy`s arabesque, thats 3 notes in the right hand against 2 notes in the left hand, but now all these chopin pieces seem to have 4 against 3 and I recently came across a rachmaninoff prelude that was 4 against 5. 4 AGAINST 5! how? HOW???

Hello, the polyrhythms are used due to their rhythmic effects. I followed succesfully the pianist Joseph Hoffman`s advice in his book: Practice hands separately till fixing the time (I use a metronome). Then use both hands, but don`t let one hand influence the other, but make use of the automatism established in the hands-alone previous practice. Be patient. Don`t discourage if the first attempts are unsuccesful. Polyrhythms utmostly embellish the pieces and worths the efforts employed to master them.

Totally agree on this! All Hands! This is how we usu practice. No point trying to calculate when or with which what the notes will come in...just do it sh until they`re even and fit em together. Di it a few times and u`ll get used to the co-ordination.

Try Jeux d`eau (Ravel). There`s 6 against 8 there - practice practice practice...