playing the piano by rotating your forearm

[pytheamateur]

I have read much that advocates rotating your forearm slightly and rapidly (about 45 degrees each way from the normal position) when you play tremolos or trills.  Could somebody please elaborate on that? 

I have a fair idea of what that involves but am unsure whether I should be doing that consciously when I practice, as my teacher does not like conscious hand/arm movements from me.  He never theorises on how you use different parts of the arms when playing to get different sounds or when tackling different technical passages.  He says I think too much about that and instead I should do everything by my ear.

Is his approach unconventional?
 

[p2u_]

Is his approach unconventional?

No, it isn't. Actually, rotation is present in ALL pianistic movements for good alignment, although the concentration of what you do should be in the fingers/fingertips. You can see this in really good pianists like, for example, Emil Gilels. Have a look at Taubman on YouTube, but don't take what they say too literally because theirs is an incomplete and scientifically incorrect explanation. Also, I wouldn't advise you to be doing this on your own. It would be best if you had someone in your neighborhood who could show you how to practice rotation elements correctly. Although your teacher is right to a certain extent, ears alone are not sufficient for many.

Paul

[pianoplayjl]

No. I only recently learnt how to trill properly. Before, all the motion came from my fingers. As I play trills with the forearm rotation, I realised how much better and less tiring it was. However I am still practicing the trill with the 2nd and 3rd finger. It is a lot harder than 1 and 3. Brahms exercise 40a helped me so much.
I wouldn't say play 45 degrees each way from the normal position. I believe that is hyperbole, unless if that source was referring to when you start learning this rotation thingy. As a person becomes profficient and familiar with the forearm rotation they should keep the rotation as small as possible. At least that was the way I was taught.

JL

[hfmadopter]

No. I only recently learnt how to trill properly. Before, all the motion came from my fingers. As I play trills with the forearm rotation, I realised how much better and less tiring it was. However I am still practicing the trill with the 2nd and 3rd finger. It is a lot harder than 1 and 3. Brahms exercise 40a helped me so much.
I wouldn't say play 45 degrees each way from the normal position. I believe that is hyperbole, unless if that source was referring to when you start learning this rotation thingy. As a person becomes proficient and familiar with the forearm rotation they should keep the rotation as small as possible. At least that was the way I was taught.

JL

The rolling forearm is great for grace notes as well, as apposed to trying to use fingers to execute them.

45 deg may be over kill but then again maybe not. depends on trill, the key board, key depth etc. And if you still use a bit of finger movement which will lessen the roll. Also don't forget your left hand trills.