The concept for Parasite Eve was based on a Japanese novel of the same name. The events of the novel take place one year before the game, and, while no characters from the novel show up, the events are referenced. There is also a movie and a manga series based on the novel.
Square Soft releases soundtracks for most of their games (or posible all of 'em), so soundtrack for Parasite Eve isn't anything unexpected, and could be found on many online stores like SynSoniq.com, AnimeNation.com or such. Music composer for Parasite Eve tracks is Yoko Shimomura. Of course, music from the game cannot even be compared in quality with the soundtrack score, as this is orchestrated, far more better quality and digitized.