Being a beginner most likely. In music clubs like these it’s the job of the Senpai to guide the young Kohai so that they’ll improve, unfortunately Mizore is quite distant to other people that it’s only later that she opened up and help Ririka
if you listen carefully her sounds is pretty but it's not stable as the sound that comes from the left which come from Mizure. If you divide the sounds from left and right and first listen one and then the other the difference will be more clear. Nonetheless it really gives a really warm feeling of un upper classmate leading and supporting the under classmate
In the title it just says "Mizore's and Ririka's oboe etude" if you're referring to all the comments I can't help you with most of those, my Japanese is too bad XD