Asuka’s motif appears in the background soundtrack over and over again. In the previous season, the OST composer did this using a clip from Crescent Moon Dance. Now the entire background soundtrack is focused on one particular euphonium etude that Asuka plays. In fact, Asuka’s etude is the FIRST thing we hear in the first episode of season 2. It is super significant.

I could say why on this post but I don’t want to spoil it for people who are coming from Reddit.