Since it's one part VisualNovel, VisualNovel/NineHoursNinePersonsNineDoors is sure to have some of the wonderful music that's usually seen in that genre. Here are samples of some of them.
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* [[http://www.youtube.com/watch?v=rA_DvZ8kQRc Quietus]]: The '''Bad End''' game over music. Starts off with a demented chime, then morphs into a metal, slightly industrial tune.
* [[http://www.youtube.com/watch?v=9GLYF5O1gMY Chill and Rigor]]: Reminiscant of Hello Zepp in {{Saw}}.
* [[http://www.youtube.com/watch?v=raQ8ATBniAQ Recollection]]: The piece from the [[spoiler: DiedInYourArmsTonight]] moment in the [[spoiler: "Submarine" ending.]]
* [[http://www.youtube.com/watch?v=0CcFdLk6oF4 Octal Game]]: A much more relaxing piece, contrasting the rest of the tracks tense feelings.
* [[http://www.youtube.com/watch?v=EjQfY47pFNs Morphogenetic Sorrow]]: A track that clearly tells you that this is the finale. The fact that it plays in [[spoiler: [[SoundtrackDissonance the Sudoku puzzle]]]] really changes the mood.
** A remix of it acts as the backbone of the [[http://www.youtube.com/watch?v=ZAqGs441qzU trailer music]] of the sequel.
* [[http://www.youtube.com/watch?v=9xJSPwvhjL4 Foreboding]]: A track that's reminiscent of [[UminekoNoNakuKoroNi goldenslaughterer]], giving quite an intense atmosphere.
* [[http://www.youtube.com/watch?v=8nVkPZOyzBE Unary Game]]: Guaranteed to induce panic.
* [[http://www.youtube.com/watch?v=9HzQzkXjIRY 9 Years]]: The music that plays during the true ending/prologue. Also counts as Crowning Music of Heartwarming due to the bittersweet finale.
* [[http://www.youtube.com/watch?v=I8HRjFRRf4E Ternary Game]]: An oddly energetic track compared to the rest of the soundtrack.
* [[http://www.youtube.com/watch?v=otY4bLTJL9k Septenary Game]]: A catchy and considerably upbeat track that plays in the operating room (Door 7) and [[SoundtrackDissonance the shower room (Door 3) that contains the grisly remains of]] [[spoiler:Nijisaki]]. A nice break from the usual chilling music.