The high hopes I had for this series were dashed after the first few minutes. The storyline felt like someone decided to animate a fanfic for a much better series. There were these honest traces of something better in the storyline. It fell flat because of the cliches within the series and because of how much of a Mary Sue the main character is.
In the first episode I was left asking why Hibiki was so special compared to all the other people who exist in this world. She's not special because she has any sort of talent, something she constantly admits. Her childhood is bland and uneventful, yet Kanade sings her Swan song in the first episode sacrificing herself just so Hibiki can live despite the fact it doesn't feel as if Kanade needed to sing her Swan song to save Hibiki's life. Instead, Kanade's death is simply a tool the writer used to give Hibiki her amazing powers so that she can be the heroine of the series.
The theme of sacrifice is another place where this series falls flat. At the beginning of the series it is played up as being a very important theme but by the end it honestly feels like a joke. It is instead replaced by the theme that everyone can get along by everyone talking things out. Everyone else has a mind frame that violence will solve everything, but Hibiki is difference because Hibiki is so innocent and naïve that she honestly believes there is a better way when people are human. In the long run, it is Hibiki's character that destroys the storyline.
Of course, Hibiki does have a few flaws up her sleeves to make the viewers not think she is a Mary Sue. She is at the beginning of the series horribly klutzy and she can't do anything right. This is fine when she first gains her powers because she has problems in her first fight. However, after this she receives no training from the government so she can fight the noise, she is allowed to run around on her own letting her klutziness in the way.
Added to this, Tsubasa wants nothing to do with her because Hibiki reminds her too much about Kanade, and yet it would make more sense for Tsubasa to protect the one thing of Kanade she has left. Many of the characters don't get fleshed out and the way Hibiki gets over her flaw is just ridiculous. Her naivity also isn't played up as a flaw either, but it is actually her strong point as it allows her an innocent outlook on life that is willing to accept everyone who is human with no qualms what-so-ever.
The art is really good and the sound is good at points, but they also like to play the main characters songs as being more special then anyone elses, including the other students from a music academy of all things.