My friend, a classical pianist, just played for me a Fantasie by Chopin which involves playing a steady 6 note left hand melody while the right hand plays 19 notes... something like that, at least. He said that you basically just concentrate on keeping the six notes going while making the 19 notes sound as even as possible. Apparently, if he concentrates on the two hands working together, it's impossible ot play. I can see how this lends itself to multiple interpretations.

Wasn't Chopin at the beginning of the Romantic period, which basically was when musicians discovered freedom within music, as opposed to the composers during, say, the Renaissance? And Rachmaninoff was definitely a Romantic composer/pianist.

As a side note, Rachmaninoff (my favourite composer, BTW) is in the Guinness Book of World Records for having the largest hand span; apparently, he could play a chord which no other human could (I don't have the book in front of me now, but I think it was 12 white keys with either hand; I'll check and repost).