Chopin was an improviser. In fact, he once wrote that he had difficulty deciding which version of his piano pieces to put on paper because he played them differently every day.
While it's possible that Chopin would change the large-scale harmonic and formal relationships within his pieces, my guess is that once these were established, his improvisations were more melody-based. Altering and embellishing his melodies within the preset overall composition.
In this respect, Chopin did us a huge favor by writing out a lot of these improvisations. Listen to this Nocturne, for example (you can follow the score on the video too). At the beginning, he states the melody clearly. But when it repeats, it's different. The basic shape is the same, but listen those wonderful embellishments! He's improvising!
Why not try it for yourself? Learn the Nocturne as written. Then, play the embellishments a little differently than Chopin did. Keep the basic shape and important notes, but play it the way you feel at that moment. And play it a little differently the next day and the day after that. Some days it will sound better than others, but that's the point. He probably played it better on some days too.
When I play these improvisatory pieces of his, I feel like I'm right there in the room with him. Even though it's me playing, I'm really listening to him play. And in a sense, I am. He's improvising and I'm listening to him do it. Then, when I improvise my own embellishments, it's me playing in his style. His music is incredibly intimate and transcends time.
Try this yourself. You have to keep at it until it becomes natural and effortless. That's when the magic begins.
If you're a classical pianist who's always wanted to improvise, a whole new world is waiting for you. Here are a few lessons to help you get started.
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