No word is more important in describing the playing of Chopin's music than rubato. It comes from the Italian word robare, to rob, but in music it means "give and take." If you steal a little time here, you've got to give it back. For example, in playing a melodic phrase, if you go forward in the first two bars, you must pull back in the next two so that the freedom you took does not break the rhythmical pulse. The classic feeling will come from the left hand, which Chopin insisted should be played as evenly as possible. Then the right hand can have its romance and play as freely as the left hand will allow. Every performer will use that freedom differently, and that is the beauty of the "disciplined freedom" that makes Chopin Chopin.
Chopin said the Polish word zal—a "bittersweet melancholy"—best described much of his music. Paradoxically, it can also mean anger, even rage, an emotion also found in Chopin's musical vocabulary. Schumann agreed, describing Chopin's music as "cannons buried in flowers." For example, listen to the Ballade in G-minor and the Scherzo in C-sharp minor.