The piano parts...are notoriously unsatisfactory. Some arrangements pile too many notes into the reduction, trying to replicate the entire score on two staves. Since a piano reduction is simply one person's idea of how to represent the orchestral harmonies on a keyboard, the collaborative pianist can with impunity use their own analysis and judgment in adjusting the piano part, using the printed edition as a starting point. Octaves may replace single notes, or single notes replace octaves. Solid chords may be broken or broken chords may be made solid. Tremolos may be added to represent sustained string sounds. The sky is the limit, providing the pianist has judgment and reason in steering a single piano to simulate an entire orchestra.