Ok, don’t panic.
First a disclaimer. I do not like to give advice on pieces I have not played, which is the case here. So whatever follows is said from a purely theoretical point of view and without seeing the score. Hopefully someone who has mastered this piece will come forward and give advice that is more practical and more to the point.
And Faulty's advice is good.
If I was going to confront such a passage as you described this is what I would do:
1. I would isolate the passage that has the technical difficulty, namely playing trill and melody with one hand.
2. I would start by playing RH only - only the trill with fingers 3 – 4. Then I would join the melody with the left hand . This will allow you to keep doing the trill in a uniform manner without having the other fingers of the RH intervene and unbalance the trill, and at the same time you will be able to explore what is the best sound - if you want to play the trill together with notes (my suggestion – believe me, it will be far simpler) or if it is truly effective as you think it maybe with pause in the trill to fit in the melodic notes. Only when you decide about the sound you will be able to decide on the technique to achieve it. So this is your first priority.
3. Remember that trills are embellishments, so the melody must take precedence over it. At the same time the trill must be even and controlled – otherwise you will be calling attention to it, and it will stop being an embellishment. This is also an athletic problem you will need to develop the muscles and stamina to deal with it. So approach it with a sports training mentality (warm-up, increase effort slowly and gradually, stretch, cool down, be consistent and persistent). Muscle takes from three to six months to grow, so doing too much too soon may land you in injury land.
4. Bringing out the melody over the trill will not present a problem, since the thumb and second finger are the strongest. Trilling with 3 – 4 will be the problem, and then co-ordinating the trill with the melody will be a nightmare. So you must master these two aspects (trill and melody) separately before attempting to co-ordinate them. So spend a long time just playing the melody with 1-2 and then trilling with 3- 4 separately. As you do that aim for the most perfect trill and for the most beautiful rendition of the melody you can manage. Also do what I suggested in [2] and use the other hand to play the trill as you play the melody with 1-2 (you may need to cross hands) or to play the melody as you play the trill with 3-4. This will get you used to the sound of it without so much technical difficulty (you can also ask the help of another pianist and share with him the trill and the melody). Also if you have access to a digital piano that has a recording/playback facility, you can record the trill and play the melody yourself and vice-versa.
5. Trilling with 3-4 for any length of time cannot be done with fingers alone. So use rotation of the forearm to help you. At speed this rotation may look to an observer as not being there at all. But you should feel it, even though it may be so small as to be invisible. Fingers 1 –2 playing the melody can also use the help of this rotation to land them in the proper place. Co-ordinating it all will be the real problem. Fortunately, our bodies are wired for these feats of co-ordination, and if you do not pay excessive attention to the minutiae of the movement, it should all come together beautifully without you quite knowing how it was achieved. But start fretting about microscopic details and everything falls apart.
6. Once you are totally comfortable with the above, you can give the big step and join everything together. But do not jump straight into it. Do something I call “dropping notes”. Play the trill for the whole duration, but only the first note of the melody. In other words, you “drop” the first melodic note, and stop, but you continue trilling until the end. Your aim here is not to let the “dropping” of the melodic note to disturb the trilling in any way. Once you can do the first melodic note comfortably and without disturbing the trill in the least, start dropping the first two melodic notes, then drop three melodic notes and so on and so forth. In the beginning everything will fall apart every time you add a new note, but after a few trials, it should come together again. Once you can do the whole passage acceptably, do the reverse process: play the melody from beginning to end with fingers 1- 2. Then add just a fraction of the trill with fingers 3 – 4 (just enough to cover the first melodic note) and play the whole melody to the end. Again your aim is to not let the addition of the trill fragment disturb the progression of the melodic line. Keep adding trill fragments to the melodic line until you can play the full passage. You may need to repeat this procedure from scratch for several days before it comes together confidently first thing in your practice.
7. All the time during the several steps of this process you should be experimenting with different movements in order to find out the one that is the most comfortable/efficient for you , for the sound you want.
8. Finally, do not practise this sort of passage too slowly until you figure out the movements that are efficient at speed. Work fast (but not too fast), and once you know the movement s that will work for you, then and only then slow it down so that you can get accuracy within that movement frame. In other words, do not practise slowly, practise in slow motion. And do not try to tackle too long a passage. Break it down and work in small sections, overlapping sections as you go along.
9. Ah yes! You cannot have independent fingers. But you can give the illusion of having independent fingers (pretty much like a magician cannot really saw a lady in half – but if he is really good he will convince you he can).
I hope this helps. I will try to have a look at the score, and I will let you know if I can think of something else
Best wishes
Bernhard.
Topic: Trill and Melody in one hand..HELP