Answer:
"effortless"
Explanation:
"less" is the suffix which negates "effort".
You're exerting strength and attempt when giving effort at a task and either don't have to (as in this case with playing the instrument) or don't when doing something effortlessly, thus the two have opposite connotations via the suffix.
X = 4 , that’s what I got ! Sorry if it might be wrong
Haikus are most likely to deal with nature.