Expressions or interpretations aside, pianists who can run fast passages skilfully (with precise notes and precise rhythm/duration) may perceive that they can play both fast pieces and slow music with similar precision/accuracy. But others who have difficulty playing fast passages can only play slower works. Thus their argument might be: A sports car can be faster than a regular car, but it can be as slow as a ergular car too, if it wants to be. But a regular car can never be as a fast as a sports car.

In fact we are dwelling into a topic that encroaches into social-politics. How do we comfort or encourage someone (who has the aspiration to be a doctor and has been working hard towards it throughout his life) who is janitor, because he failed to make it to becoming a doctor or any other white-collar professions? By the same token, we know of several instrumentalist-aspirants who have been learning to master the playing of piano for decades but they can never reach the technically-challenging levels required of most classical piano concertos. What should we be telling this person?

Verdi, as we know him, is one of the greatest composers, especially in writing Opera music. But did you know that he was very poor in playing the piano? But his music works are supreme! Which explains I don't agree with Howard Gardner's Multiple Intelligences, which sees Musical Intelligence as one unique factor in mankind. My point here is: While someone is excellent as an instrumentalist but poor at composing, other are the opposite.

Zensen: In terms of performing ability, there are more objective methods to measure this. However, if we're talking about composing ability, like what you said, it's a different matter altogether. That is why, very few child prodigies grow up to become geniuses who change the world. Because while these prodigies are excellent at playing music or are very knowledgeable in whatever field they're in, they rarely produce anything original.

I am neither a concert pianist nor a composer, but I don't consider myself a failed musician because, my mission is to spread the lifelong love of piano music to others, and that's enough meaning and purpose for me.