Originally Posted by yenraBdellikI
Alright, I'll chime in. I believe that this question is not only unanswerable, but just plain fundamentally wrong.
It's not possible to compare the difficulty of playing various instruments, because the idea of "playing" or "mastering" or whatever-word-you-choose-ing an instrument is completely vague. I'm having trouble putting my thoughts into words, but the basic idea is that comparison is impossible.
For example, if you were to compare the hands-down world's best drummer and, say, oboe player, the oboe player would show unmatched skill, as would the drummer. But the reality is that there would be no point of reference; no way to judge; which one was better at their instrument, because they themselves are the standards of perfection. Neither can be better, since they're both the best.
But we all know that this standard of perfection does not exist. We can't decide which instrument is the hardest because people will always attempt to achieve perfection, and perfection is defined by people's ability.
I'm with you on this...different things are difficult to different minds. Our bodies are all capable of playing the instruments, it's just a matter of instructing them correctly, and that's true for any instrument equally.