Right now, I am learning to play Nuvole Bianche by Ludovico Einaudi (here is a link:) and I need to have a recording done by tomorrow for the piece. I started learning it on Thursday and I spent ages doing it. When I am not recording it, I make no mistakes but when I am recording, I keep on stumbling about 2 mins into the piece. I've tried sleeping on it but that doesn't work. Help please!
My advice is to make a lead sheet where you write the chord progression and another sheet where you notate the melodic patterns and the fingerings - almost every bar has a repeated motif - thus it won’t be difficult to get a reduction to the essential changes.
If you really play from this system shown in the video it’s no wonder that you struggle. You have to look ahead and must know what’s coming as next.
So you have stage fright in front of the camera? I'd have to hear the kind of mistakes you are making to know what is going on but it is probably one of three things:
You don't know the piece as well as you think. It is not enough to be able to read the notes and match them to keys. You must know where they are going, the progressions, intervals, keys, scales and chords. This means knowing music theory and training your ear and dissecting the score. This is much like memorizing the first bar on page turns except you must know the entire score. When something makes us nervous, our brain shuts down and we function on autopilot. If you know the story of Goldilocks and the Three Bears and I started telling you the story in some random scene, you would know exactly where I was and what comes next. Music must be learned the same way. You must enflesh it. Then, even if you are nervous, you still know where you are. Merely matching dots to a key does not make a literate musician.
The second area which can cause us failure is improper technique. Many of us move incorrectly and while relaxed we can get through it with brute force but when we get nervous, that control shuts down and we are left with motor memory and the problem with muscle/motor memory is that it also includes every bad habit we've ever had even though we overcame them. You could have learned to play in your early years with improper movement but corrected them years later. When you are nervous, those old improper movements can come back and cause us to miss notes. Worse, the improper muscles we augmented in the past have since atrophied and this will cause strain, cramps and sloppy playing. It is a downward spiral. Practice does not make perfect. Knowing physics, anatomy, ergonomics and what not to do makes perfect.
The third flaw we may carry is - we make music to share, to express, to communicate. When you give something away, the focus is on the person you are giving it to. If the camera comes on and YOU try to be perfect, you may be focusing on you and not making music.
Being nervous can rob you of everything but if you know what you are doing, you will not only be less nervous but you will remain in control of your mind, body and music.
When scared, our body enters into sympathetic reflex or "fight or flight." Being nervous while performing has the same response. Our blood pools FROM our extremities to our core to protect the major organs. This robs our muscles of blood and oxygen, they contract, that tightens our tendons and our fingers are no longer free but now fighting this built in tension of contraction. They may feel cold. You may make a mistake or begin missing notes or leaps and you may feel your hands are not yours. They are not, they are the hands of the you when you first touched the piano, this is what your brain knows best because it was first hard wired. Muscle memory reverts to what it first learned. Proper or improper. Proper technique relies on the brain making constant adjustments to maintain ergonomic movement, when nervous that shuts down and motor memory takes over.
The solution will take time. Learning music theory, study the score away from the piano, train the ear, play to communicate, make sure your technique is built upon the knowledge of physics and not just repetition. Then if you ever get nervous, YOU will still be in control and not muscle memory.
Learning to play music doesn't work like that. Even assuming you have the fundamental skill level to play the chords, sequences, etc. at the required tempo, our bodies & in particular our nervous system don't "learn" based solely on total practice time. Some of the learning requires multiple days (or weeks) for the abilities to pass from short-term memory to long-term memory and into so-called "muscle memory."
It's great that you put a ton of practice time in, but there's strongly diminishing returns after maybe a couple hours (on a particular piece) per day.
That said, if this is purely a recording problem and not a performing problem, then certainly recording small chunks and combining in post-processing is the way to go.