I don't think that fast, loud, widely-spread chords require any specific physical technique. Passages containing this type of material certainly require lots of deliberate, slow practice. But you shouldn't have to think about what movements you are using in that slow practice. The movements should come naturally. Your overall technique should be able to accommodate a wide range of musical material. Be careful with allowing your wrist to come up too high. We want to maintain a straight(ish) flexible line between the elbow and the knuckles for optimal energy transfer. If the wrist comes up too high, this line buckles in on itself, and our tone can collapse.
What I tend to do is to close my hand as soon as possible after I play the chord, and to use more arm/body weight to press down on the keys, along with a high wrist to facilitate that with fingers remaining close to the keys.
Hey awesom_o,I can and have played most of the Chopin Etudes, except for the sixths and the jumps (both in op.25), might try them out one day. The fingers must all be "stiff" enough so that they don't buckle, and this takes quite some strength from the hand. Do you think it's just a issue with hand strength?
faulty_damper:I know that pressing down is a bad idea in general as it tenses up the forearm muscles. I always believe that piano playing is more about the speed of attack rather than using brute force. What I meant by "pressing down" using bodyweight/arm (probably a pretty poor way of expressing it haha) is to come up from high and attack downwards using the weight of the arms and bodyweight for energy. awesome_o:I still think that the fingers cannot be "too relaxed" that they become a little floppy when playing chords (which causes more strain), it must be "stiff" enough to prevent that from happening. Of course one cannot stiffen it up to the point where you introduce strain into the picture. I improvise plenty, and also like to dabble in compositions (for both piano and Chinese pop LOL). But I have a lot of half-baked compositions which I never had the time to complete...
... What I meant by "pressing down" using bodyweight/arm (probably a pretty poor way of expressing it haha) is to come up from high and attack downwards using the weight of the arms and bodyweight for energy.
That's the same thing as pressing down which wastes energy doing nothing. Try it the way I suggested and I guarantee you'll notice a significant improvement AND it's faster and easier.
I am thrilled to hear that you improvise regularly and also compose! Having a ton of half-baked compositions (and being quite poor) is the unfortunate reality of being a composer! Over time, our ability to see a project through from beginning to end increases. You are absolutely correct when you say that piano-playing is more about the speed of attack than using brute force! You are also absolutely correct that 'too relaxed'=floppy With sufficient training and experience, the fingers can acquire the qualities of spring-steel: highly flexible and elastic, but also extremely strong. In a word, supple. Chopin loved the word supple and used it in his teaching very frequently! It is the strength of a gymnast that we must cultivate, rather than the strength of a weight-lifter or bodybuilder. TOO relaxed=the qualities of a wet noodle!
I understand what you mean, I also go 45 degrees into the piano and bounce upwards if I am playing relatively slow big chords, but if it's fast, I think this would require too much "recovery time" to even be viable. I'm talking about fast chords like my example of the section in the Rachmaninov Prelude in B flat major. Bouncing from key to key is a great idea though!