Sometimes, small steps can have a profound impact. That's why it's often beneficial to focus on deepening rather than broadening. When something improves at its core, everything changes—the sound, the way it's played—in all the pieces.
In such cases, it's important to take the time and give yourself some rest to delve deeper into fundamental aspects of piano development and truly immerse yourself in them. You have to allow yourself that time. I've been working on the classic tune "If I Should Lose You" for the past two months. Although I had played the piece for years, I wanted to explore it more deeply.
It starts with D7 to Gm, and perhaps you can incorporate some altered or diminished scales into it. Maybe try D7alt to Gm711, and so on. But what about the essence of the title, "If I Should Lose You"? What color resonates with it?
As a drummer, how do you approach this on your cymbal? Is it a bit darker, closer to the bell? Do you play it right on the cymbal or at a different angle? Do you hold the stick a bit tighter, allowing the tip to dampen the vibration, or do you let it fall loosely, keeping the sound open? These are choices—choices that may go unnoticed at first. When timed well, they won't interfere with anyone. However, if you take a week to experiment and find what works best, what produces the best sound, you'll deepen your control. And I assure you, "everything will improve."
This applies not only to this particular piece but also to the other 100,000 pieces. As your control increases, you'll be able to make clearer choices, and you'll develop a heightened perspective, perception, and control of your craft. Eventually, you won't consciously think this way during a concert, just like the audience, but something will have changed, something will have deepened.
As a pianist, you can immerse yourself in the colors, rhythms, and melodies. Generally, I spend a month or two working on a new piece, experimenting tirelessly. And afterward, something changes in all my repertoire.
While there's nothing inherently wrong with tackling many pieces and diverse subjects, delving into the core of a single problem leads to overall improvement. Moreover, this approach doesn't consume as much time as you might think; in fact, it becomes a tremendous time and energy saver.