Liszt broke the strings simply playing too hard... but, of course, you could easily say that he shouldn't play that hard, if he knew they were going to break!

Pushing an instrument into sonorities and performance techniques it wasn't designed for can often have consequences. But where would we be if those guys didn't TRY those techniques?

Still playing the fortepiano? Or the virginal or harpsichord? Instruments are the way they are now BECAUSE they were built to withstand the 'abuse' that earlier generations put onto the instruments of their day. And if being more percussive and using a piano as a source of sounds you don't get simply from tickling the ivories ends up in a more modern piano that resists going out of tune when banged around, we are going to be THANKING guys like Jamie Cullum, just as we thank Liszt for the strength of the modern piano.

PLENTY of mistreatment of instruments in the legit avant garde world... I've dabbled my share in 'prepared piano' back in my college days You would probably have hated that, too, Tony