I thought music as a set of languages is way easier than it happened to be. A CS degree and passion for linguistics doesn't convert into fluency as fast as I wished, and now I see why I'd need 4 years of music college + 4 years of an actual degree.
I love comparing the differences between piano and guitar as instruments for learning music. They have such different strengths and weaknesses. Changing keys with a capo is like using the "pitch shift" button on an electronic keyboard. Since music is only a strong hobby of mine, I have never come to any conclusion on those matters.
I learned a LOT when I received a free high-quality piano (that had been in storage) and decided to tune it myself. That's a rabbit hole I am still amazed by. I got a lot of use out of http://piano-tuner.org/ Piano tuning is such a complex art and science.