One of the composers did a remix for this tune, and judging by the reception and his comments, an arrange album might just come out.
Emi's "Standing Tall". It sounds as if the composer's telling you, "Look, a beautiful girl. She's athletic, cheerful, playful, childish, full of energy, she has a smile that will light up your day and has always an optimistic attitude in life, no matter what happens. What could be wrong with her?..."
Unfortunately, it also plays at the emotional breakdown of EVERY good ending. And Emi's turn with this song plays it regardless of whether you triggered her Good or Bad Ending, during the scene where the difference mattered. Guide Dang It.
"Innocence", a very softly understated song that both leads into Lilly's Love Confession, and plays during Hisao and Hanako confessing to each other, and realizing what missteps they've made along the way. It also plays in both versions of Emi's good ending, when Hisao manages to bridge the gap that has appeared between them and finally says that he loves her.
"Jitter", the song that plays during the animation at the start of Hanako's route, is at first forlorn, then overwhelmingly hectic, and finally... serene and calm.
"Breathlessly", a heartrendingly lonely piano piece reserved for some of the most tragic moments.
"Wiosna", meaning 'Spring' in Polish. An uncomplicated song that plays in the main menu, comprised of a single piano, and some sort of guitar. What we get is a calming and subdued piece that is lonely and wistful, nostalgic and quaint; a piece that fills this troper's heart with melancholic satisfaction, especially after completing a route.
Actually, all of the songs work for this trope, as every single one is easily connected to the type of scene it corresponds to. "Painful History", "Shadow of the Truth", "Caged Heart" and "Stride" all have a somewhat sinister tone to them, denoting the seriousness of the scenes they appear in, while songs such as "Innocence" and "Romance in Andante II" are easily connected to the romantic scenes, especially Lilly's Crescendo sequence. Even the "Generic Happy Music" is awesome!
"Friendship", which apart from Kenji's glasses removal scene, only plays during Lilly's and Emi's good endings and Rin's neutral ending. A soft song, bittersweet tune that really lampshades Lilly's farewell and, if you took the right choices, Hisao's determination to convince her to stay at near impossible odds. Meanwhile, it also gives the tune to when Emi finally lets Hisao close while finally being honest about her accident which also claimed her father. Finally, it also lampshades Rin essentially breaking up with Hisao at the art exhibit and ends their friendship reluctantly in the rain with a farewell hug.
"Aria de l'Etoile" is another one of those pieces that plays during the more beautiful scenes, including Rin and Hisao's first kiss in her bedroom, Rin's ending scene, Emi's ending scene, falling asleep next to Hanako, and Lilly making the origami crane.
Cold Iron, the track that plays during Hanako's panic attack making an already stressful and emotional scene even worse and really points out Hanako's mental scars. It also plays in the first scene during Hisao's first heart attack, another heart attack in Lilly's route, and Hanako's bad ending.
Romance in Andante II, a beautiful tune you might hear in specially romantic moments, like Emi and Hisao's first kiss, Shizune accepting to be Hisao's girlfriend or Lilly thanking Hisao with a kiss for giving her the music box and her confession of love towards him some scenes later.
And finally, Romance in Andante, a short but beautiful piano melody that only appears in the Happy Ending credits sequence from any girl's route. It simply fits.