Nocturne in Db - Arensky by Stephen Ngai
It is not easy for a teenager to play an expressive piece because this is all about inner emotion. Teenagers may not be willing to express their feelings or not have much experience to feel the in-depth meaning of music.
This student, after practicing intonation, rubato and breathing several times, finally finds his way to interpret this piece. I can tell he improves a lot about expressing himself truly. Keep it up!