Anyone knows what sounds good, but not everyone knows why and how to do it again and expand on it
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Like I said, it's not essential, you can fully understand music without knowing a single thing about sheet music, it's just the most popularly understood language of music, and despite it's many pitfalls and archaic baggage, it still is useful.
The actually theory is more to do with cadences, forms, passages or phrases, scales and modes, harmony, melody etc... and sheet music is generally used to explain these things.
There are more ways to learn songs these days, but sheet music is still the most widely available, understood and doesn't require anything but, well, paper.
The way I see it is you are trying to make excuses for not learning something that isn't that hard to come to grips with that only limits you if you don't know it instead of giving you more freedom.
The fact of the matter is sheet music and the keyboard layout have very close ties, I don't know if the keyboard was designed according to the way notation is or notation was made according to the way the keyboard was laid out, but it's one of the two.
But, at the end of the day, it's up to you.
But, with regards to learning things specifically related to the keyboard instrument and not just all instruments, I had my first lesson today, and I'll make a summary of all the cool things I learned and exercises that can help.
Ironically, this is a prime example of why you should be able to read sheet music, because I could have just sent you the piece I got to practice(basically combines a bunch of the technique exercises into a simple song) straight away but now you will have to wait for me to learn it first and record it before I can give it to you