Tense arms while playing Rachmaninov

Right well I'm learning Rachmaninov's prelude in Csharp minor, and there's a bit from the bottom of the third page to the top of the fourth page (if you know what I mean) where both the hands play small, quick chords in triplets. I can't play it in time - the hands (which should alternate) end up playing simultaneously, it's far too slow, and my arms get really tense when I play it (which I think is the cause for the other problems). Now I've tried everything like slowing it down, relaxing the hands and arms and all that but it just won't work! Any suggestions?

Oh and by the way, my teacher has told me to leave it, because it was apparantly good, but I'm still learning it, only not with him. I want it really good, not just 'acceptable'.

The trick is feeling the pulse even though the hands are alternating.

Trying doing the same pattern with a different chord, as sort of a training ground. Maybe take a simple C# minor or C major triad in both hands, and just play that chord in triplets, accenting the first of each triplet but alternating between the hands so that the accent falls on left, then right, then left, and so on. Start very slow with a heavy (but relaxed!) accent, then speed up making sure the accent falls ONLY on the first note of each triplet. Pay attention to your arms: are they relaxed? are they in an 'L' shape? Always lean in towards the keyboard using your weight instead of your arm-muscles, the less muscles you use, the less tension that can develop. Are try just throwing yours arms around, let them hang limply, loosen your shoulders regulars. Tense shoulder are often overlooked.

Welcome to YC, by the way! Are you here to stay by any chance?

If you're not already familiar with Chang's book; "The Fundamentals of Piano Practice", you may find it helpful. He has some pretty insightful ideas concerning various aspects of playing the piano. I found his suggestions to be quite helpful on a number of levels, not only with piano practice, but some of his ideas actually helped me on the violin as well.

Piano Lessons: Learning and Teaching Piano, Piano Tuning.

Thanks for the advice, that book looks really good.

I should stay here, this looks a fairly nice site to be on.

I should stay here, this looks a fairly nice site to be on.

Oh but it is!