Hey all. Before reporting this as a bug, I just wanted to check whether or not I'm doing something wrong.

Either the first or second night after you get the quest to investigate Evgeny and Anastasia, I met Anastasia and then she offered to teach me piano. Since that event, I have not found her in the music school even once. I don't know if she's only there at a certain time of night, and I just keep missing her? But one of the very first side quests I got was for Piano Lessons, and I just haven't been able to take a single one. Am I missing something? 

I can't remember all of the days that she is at the school. However, I do know for a fact that she is (or should be) at the school on Wednesdays and Saturdays. 

Yeah, I ran into the same issue. Anastasia only shows up at certain times, and I kept missing her at the music school. While waiting, I actually signed up for some IRL lessons through artmaster.com – it helped me get a handle on the basics, haha.