She thus uses the calculated frequencies and other musical parameters to generate electronic sounds as well as the instrumental score performed live. When notating the scores of "Book of Mirrors" and "Roseherte" Hirs started out approximating the frequencies to the nearest halftone. During the creative process of composing "Roseherte" Hirs decided to approximate into quarter tones. Since then many of her compositions have been notated in quarter tones. The electronic sounds in Hirs's compositions are synthesized using the unapproximated frequencies and provide a means of reference for the musician during rehearsal and performance. In this way the role of the electronic sounds is two-fold, both as constituent to the music as well as a reference base for the performer: the electronic sounds shape the overall music and inform the instrumentalist how to adjust the intonation of the written pitches. Playing with sound in multiple layers of meaning and with multiple possibilities for reading leads to a ‘fluid’ poetry. Among these layers, the reader may choose again and again, thus to a large extent shaping his own reading experience. A multiplicity of reading possibilities and identities has become Hirs’ poetical trademark, forming a bridge to her music. In 2010, her CD "Pulsars" was released. On this CD, Hirs investigates polyglot language and the simultaneity of streams of meaning in three electroacoustic works using original texts in English. On 10 May 1991 Rozalie Hirs presented her poetry for the first time to the public at the student festival for culture "De Pythische Spelen", Enschede. She received the third prize for poetry and an invitation by Jan Kuijper, the renowned Amsterdam-based Querido's principal poetry editor at the time. In 1992 Hirs's poetry debut was published by the literary magazine "De Revisor". In 1995 she was awarded the first prize for poetry at "De Pythische Spelen", Amsterdam. Querido published her first poetry book "Locus" in 1998, followed by "Logos" (2002), and "Speling" ("Leeway", 2005). Hirs' work was selected for "De 100 beste gedichten van 1998", "2002", "2005", and appeared in poetry collections, and literary magazines in The Netherlands (De Revisor, Tirade, De Gids, De Tweede Ronde, Lust en Gratie), Belgium (Poëziekrant, De Standaard), and Germany (Akzente, Carl Hanser Verlag; Sprachbuch, Ernst Klett Sprachen; Bohrmachine, Akademie der Künste, Berlin), and the United States.