15 October 2025. Today, a wonderful review by Aart van der Wal on Hirs’ album Infinity Stairs (2025) appeared in the Dutch online magazine Opus Klassiek. Read the English translation of the article here:
Aart van der Wal: Infinity Stairs
In May 2018, Siebe Riedstra discussed a number of works by Rozalie Hirs (b. 1965, Gouda): Platonic ID for ensemble, article 0 for percussion, articles 1–3 for piano, article 4 for violin, and Book of Mirrors for ensemble.
There he also touched on the ideal of this versatile artist, who moves with ease between music, poetry (she is also an acclaimed poet), science, and technology:
“Shall I tell you what my ideal is? That I learn to write a kind of music that engages in dialogue with the physical and psychological processes of the brain. A music of the senses, communicating with the listener. Ideally, I try to give the listener an experience they have never had before.”
That is what drives her artistically and constitutes her artistic credo—then and now. Nor did it come out of the blue, as her “baptismal record” shows. To begin with, there was from early on her great interest in language (poetry) and music, seen as well from a strongly scientific and technological perspective—interests that also nourished her singing, writing, and composing. From her teenage years she studied piano and voice, and later chemical engineering at the University of Twente (Master’s, 1990). From 1991 she delved into composition with Diderik Wagenaar at the Royal Conservatoire, and later with Louis Andriessen. From 1999 to 2002 she pursued further study with Tristan Murail at Columbia University in New York, this time focused on spectral music. In 2007 she obtained the Doctor of Musical Arts degree (dissertation and composition on the aforementioned Platonic ID), devoted to contemporary and spectral compositional techniques and the software used in them, including OpenMusic.
What Rozalie Hirs creates in her vocal, instrumental, and electroacoustic music is not only exceptionally accomplished but also unique. By applying spectral and psychoacoustic phenomena with the aid of computer software, frequency analysis, sum and difference tones, microtonality, and electronic (and thereby acoustic) resonance, she brings the listener into contact with a completely new world of sound—a world in which, alongside an inspiring wealth of ideas, technology plays a dominant role. But there is more: the avant-garde interweaving of “ordinary” musical instruments with electronics.
The ingenious and distinctive nature of Hirs’s concepts has brought her many prestigious commissions, including from Amsterdam Sinfonietta, ASKO|Schönberg, Klangforum Wien, Ensemble Musikfabrik, and the Radio Philharmonic Orchestra. Her work is performed at the most prestigious music festivals at home and abroad, including the Holland Festival and the Donaueschingen Festival dedicated to the newest music.
What does her music ask of the listener? That is not easy to capture in words, though it certainly calls for a generous measure of openness. There are no classical, traditional, or conventional patterns supporting her musical creations. In the most literal sense it is a new sound—and thus also a new way of listening. The reviewer (and surely not he alone) is thereby faced with the impossible task of describing this music adequately. Listening, and undergoing the spectrum of sound without preconception, is the only answer. What helps in this respect is that the development of sound in Hirs’s pieces often proceeds slowly and fluidly, almost dreamlike or even meditative. It is as if the spectralists were laying an aural magnifying glass upon sound and letting us listen into the interior of a tone as it slowly unspools.
Because Hirs’s music springs from her extremely refined aural and unique imagination—thinking in frequencies, microtones, and spectral structures; sound as matter—she enters a terrain that is unfamiliar to most listeners. The auditory experience is not analytical, but that of a field of sound: an atmosphere of sound that unfolds. There is no clear melody or rhythm, but there is an intriguing interaction between electronic and acoustic resonances. Hirs cannot and will not expect the public to understand everything; she can only hope that it opens itself to her music. That amounts—as I have already noted—to an entirely different way of listening. An important aid here is the commentary in the CD booklet and on her website.
The use not only of software and electronics—which lend themselves relatively easily to all manner of processes and moreover are not bound by human limitations—also requires collaboration with carefully selected instrumentalists. Unlike in traditional musical forms, they must be able to handle microtonal structures and to act in coordination with electronics. That asks much, both of the performing musicians and of the instruments. But it also asks much of the composer, who thereby embarks upon a far more complicated trajectory than merely conceiving and working with electronic phenomena.
The five musicians on this album—each performing at the highest level—create, each in solo works (in the final piece Infinity Stairs there are all three together), a fascinating sonic image of absolute rhythmic precision and a perfect sense of timing, with extremely varied playing techniques, alongside the ability to hear and to intone perfectly the most complex overtone structures. One should bear in mind that in microtonality the pitch intervals are smaller than a semitone (for example, one-fourth or one-eighth of a tone).
In the recent article 10 [prismes] (2021) the exact frequencies are notated, to which the musician must literally tune (in Hz). The earlier article 5 [delphin, gekrümmte zeit] (2008) is notated in semitones; the other four pieces on the album in quarter-tones. In these pieces, the absolute frequencies were first calculated within a continuous frequency space, then rounded to semitone or quarter-tone steps. Here one recognises the idea of playing along with the (acoustic) sound space. It seems that Hirs and her performers together explore the limits of their instruments and are prepared to experiment with sound and space.
In Hirs’s discourse it is not a matter of expression in the traditional sense (pathos, contrast). Rather, it is a matter of strictly measured intensity, in which the long spans of tension admit no theatrical expressiveness — nor is any needed. The focus lies on absolute control of the most delicately nuanced timbres. Even the slightest change in pitch or resonance can produce striking effects in the relations between sounds. Alertness and inner stillness here are no opposites, but merge seamlessly within this sonic image.
Infinity Stairs — endless stairs: frequencies overlapping to form an acoustic “staircase” of resonances. For the listener this evokes a meditative, undulating sound space in which time and pitch flow into one another. In this connection one might recall Wagner’s Parsifal (Act I, Scene 3), where Gurnemanz says: “Du siehst, mein Sohn, zum Raum wird hier die Zeit.” (“You see, my son, here time becomes space.”) The movement of Parsifal and Gurnemanz there arises solely through music, light, and mise-en-scène.
From the CD booklet comes this passage:
“Notably, articles 6–8 can be performed with optional electronic sounds and were designed to be played simultaneously as the trio infinity stairs (2014), with or without electronics; these three solo compositions can also be reimagined as various duos, though these have not yet received separate titles. Composed for adventurous contemporary musicians, they represent a critical phase of research and discovery for Hirs.”
Also interesting are the remarks concerning articles 6, 7, and 8:
“Article 6 [waves] (2013) and article 8 [infinity] (2014) were composed consecutively, with each drawing material from its predecessor. waves reinterprets the overtones from ways to climb a mountain as fundamentals, while infinity derives partials by treating waves as a sequence of fundamentals. The resulting frequencies were approximated to the nearest quarter tone, and durations were first calculated in continuous time before being notated in practical rhythms. This interconnected approach fosters both inner resonance and unity among the works, despite their virtuosic demands.”
Naturally, Hirs is not the first nor the only composer to engage with the mathematically grounded concepts of spectralism and overtone series. A glance at the lineage reveals both familiar and lesser-known names: Gérard Grisey (1946–1998), Hirs’s teacher Tristan Murail (*1947), Hugues Dufourt (*1943), Michaël Lévinas (*1949), Roger Tessier (*1939), Kaija Saariaho (1952–2023), Magnus Lindberg (*1958), Georg Friedrich Haas (*1953), Claude Vivier (1948–1983), and Jonathan Harvey (1939–2012) — and even this list is far from complete.
For Hirs, frequency calculations are never an endpoint but — so we read in the booklet — merely one of the “tools” for creating rich, resonant harmonies and sonic coherence. Ultimately it is the composer’s intuitive ear that decides which of the calculated harmonies and rhythms find their place in the final score.
Perhaps the foregoing has created the impression that Hirs’s composing by definition implies the use of electronics. That is not the case, as the present album also shows. The articles are technically very demanding. Articles 5–8 and the trio for flute, bass clarinet, electric guitar Infinity Stairs are spectrally rooted and employ a method based on specific frequencies. This requires utmost precision in pitch and rhythm.
Article 10 [prismes] for solo cello is another telling example. The work, written in 2021 on commission from Radio France, revolves around the spectral exploration of tonalities. It breaks tones and chords into harmonic partials or overtones, creating luminous harmonic textures reminiscent of light refracted through a prism — hence the subtitle. The shimmering melodies flow together in waves and thus evoke a constantly changing sonic landscape. By applying layered frequencies, Hirs enables the listener to perceive subtle shifts in texture and color — comparable to the play of light within a multifaceted prism. The piece unfolds in waves of sound, with gradual transformations and finely woven variations that convey a sense of fluidity and organic growth.
How, in fact, does spectralism stand in our country—originating in France in the 1970s, with Grisey, Murail, and Dufourt as central figures?
In the Netherlands there has not, as yet, been any formation of a school: spectralism found only individual application and stood at the edge of a broad spectrum of pluralistic currents (minimalism, conceptual music, post-serialism, new complexity). Only from the 1990s onward did a renewed awareness of sound structure, acoustics, and perception emerge — partly through the influence of IRCAM, spectral-analysis techniques, and collaboration between composers and scientists. Within that context several Dutch composers, among them Jan van de Putte (b. 1959 — seeking an “inner sound space,” the perception of time as lived experience, related to Hirs yet more spiritual) and Robin de Raaff (b. 1968 — for whom not the system but the tension and expressivity of music are decisive), developed their own poetically inspired variants of spectralism.
Spectralism has therefore not led to a true “school” in our country. It should rather be seen as a field of personal interpretations. Whereas the French pioneers — and now Rozalie Hirs — proceeded from scientific analysis and computation, translating the calculated frequencies into the score, the Dutch composers mentioned link these to poetic, spiritual, or dramaturgical dimensions. In the works of Rozalie Hirs, Jan van de Putte, and Robin de Raaff, spectralism thus becomes a means of exploring musically the experience of time, colour, and consciousness, and of sharing that experience with the listener — as a perception of the very nature of things.
(Read the full review (Dutch) on Opus Klassiek, 14 October 2025)