Essay 'music, painting, intuition, and calculation: Sedje Hémon and the Stedelijk Museum '
Maurice Rummens and Claire van Els
"In the annals of art history, Sedje Hémon emerges as an artist who succeeded in developing a truly distinctive artistic voice beyond the conventional practices of visual art and music. Distinctive not in the sense of having something to do with synesthesia, in which the perception of a sound stimulates the experience of a corresponding color, but rather in the manner of being unique and original in achieving the convergence of painting and musical harmony.  This can be observed in her use of tracing paper to create a grid with spatial note images of her linocut work Harmonie (1964), with pitch lengths on the Y-axis and pitches on the X-axis, the process enabling the linocut’s performance as music."
SEDJE HÉMON Harmonie (extract), 1964. Translation from painting to musical score. Source: Philip Peters and Michiel Morel, Sedje Hémon, Componist van alle kunsten
Hémon developed the method after being told repeatedly by numerous people that they could sense music in her paintings, and after Hans Jaffé, then deputy director of the Stedelijk Museum, advised her to carve a path of her own and pay no attention to what others had written about the relationship between visual art and music. According to Jaffé: “She is the only person who, following years of research and perseverance, has managed to unite the two arts, has succeeded in integrating the arts of painting and music, a dream that has eluded artists for centuries.”
This essay explores Hémon’s relationship with Stedelijk, particularly regarding the cultural context of her work and the similarities between her views on art and those of Jaffé and former Stedelijk director Willem Sandberg. Relatively little has been published about Hémon’s work, and her own book Hémon’s integratie der kunsten (Hémon’s Integration of the arts, 1996) is still considered the most important source of information on her artistry and working methods. Her distinctive oeuvre has attracted increasing attention in recent years, but little has been published on the (art) historical context in which the work was created. It is therefore necessary that we place her practice in this context and establish its relationship with contemporaneous artistic ideas and practices, beginning in Western Europe. The exact details about Hémon’s relationship with Jaffé and Sandberg require further investigation and are largely beyond the scope of this more general art historical overview.
In 1957, the Stedelijk Museum bought two paintings by Sedje Hémon, made in the same year, Pensées (Reflections) and A volonté (At will). She’d offered them to the museum after they’d been confiscated by customs officers while in transit; all the Stedelijk had to do was pay the delivery charges, 173 guilders and 53 cents, which today would amount to roughly 601 euros. The index cards for the works note that they had been acquired on their return from the section Musicalistes, non-figuratifs et abstraits, which had run in Paris as part of that year’s Salon des Indépendants, the city’s annual exhibition of independent art. The bureaucratic nature of the incident with customs is painful in light of Hémon’s experience of the Holocaust, in which she lost almost everything she held dear: her parents, who were murdered by the Nazis in 1943, and her health, which suffered as a result of the beatings and hardships she endured during captivity in four separate concentration camps, forcing her to give up her great passion, her career as a violinist. It is a sign of her unyielding character and inventive spirit that, even as an emerging artist, she was able to turn this administrative problem into something positive, as a result of which the paintings ended up in the Stedelijk’s collection, even if this “acquisition” brought her no financial reward. In 1959, Hémon donated five linocuts to the museum through Sandberg, and another nine through Jaffé in 1960, followed by an additional six pieces in 1964 through Jaffé again—a total of twenty works on paper.
SEDJE HÉMON À volonté / At will, 1957, oil on canvas, 81 x 65 cm, Stedelijk Museum Amsterdam © Sedje Hémon Foundation Photo: © Marjon Gemmeke
Hémon debuted as a painter in 1955 in the Salon des Réalités Nouvelles’ group exhibition at Musée d’Art Moderne de la Ville de Paris. She had her first solo show in 1956 at Galerie Colette Allendy in Paris, which had earlier provided a platform for other female abstract artists, including Dutch painters Nicolaas Warb and Frieda Hunziker. At the time, both Jaffé and Sandberg were still strongly oriented toward the contemporary art scene in Paris. Sandberg boasted several contacts there and kept abreast of the scene’s artistic developments through invitations, catalogs and art magazines. Accompanying the Salon des Réalités Nouvelles’ exhibition was a catalog without images and an album containing photographs of the participating artists’ works, with each artist represented by a single image they’d chosen themselves and a brief description. Hémon’s entry consists of a photograph of her painting Duel des sexes (Battle of the sexes, 1954), but does not include a description. The catalog lists eight works under her name, all with French titles, as was customary, including decidedly captivating ones such as Logique de femme (Logic of women), Duel des sexes, L’optimiste, (The optimist), Mon père avait raison (My father was right) and Abattement (Depression), which might suggest the works as expressions of the artist’s feelings or convictions. But Hémon was not one for such unambiguous interpretations:
"I paint only when I feel the urge to do so, not because I must. And once I finish a painting, I’d be hard-pressed to explain what it means. It’s like a piece of music, of which everyone has their own interpretation. Some find this objectionable, but I actually consider it a compliment if a painting is seen to offer many possible readings. Every definition is a restriction on freedom."
SEDJE HÉMON Eclats, 1964 or before, linoleum cut, 49.4 x 64.5 cm, Stedelijk Museum Amsterdam © Sedje Hémon Foundation. Photo: © Marjon Gemmeke
The catalog  also lists her address in The Hague, identifying her as a Dutch artist.
"She’d been born Sedje Frank, but went by the French-sounding surname Hémon in memory of her parents— “Hé” from her mother’s first name, Heintje (Hendrika), and “mon” from Simon, her father’s name."
Founded in 1946 by, among others, art dealer and collector Fredo Sidès, Sonia Delaunay, Nelly van Doesburg, Jean Arp and Antoine Pevsner, the Salon des Réalités Nouvelles’ exhibition had been one of the most important annual art events in Paris since the city’s liberation. Initially intended to promote geometric abstract art (art concret), it grew to encompass organic abstraction, the more handwritten, so-called lyrical abstraction and art informel. It presented household names alongside emerging artists, though members of the Salon committee would sometimes reject submissions that did not meet their criteria of abstraction, as happened when Yves Klein submitted some of his monochromes in 1955. That year’s vice president of the Salon committee for painting was the painter Henry Valensi, who, earlier in 1932, had launched the “Musicalistes” movement and founded the Association des Artistes Musicalistes (Association of Musical Artists), which had held an exhibition at the Stedelijk in 1936. Valensi’s ideas about “listening to paintings” and his Futurist-inspired imagery, among other things, were quite different from Hémon’s, but their mutual interest in music may have contributed to her selection as an exhibitor. And thus Hémon was suddenly in the company of artists from across the globe, including the Middle East and Asia.
The representation of female artists at these shows was quite low, relatively speaking, but some nevertheless managed to achieve prominence in the local art scene. Thus, works by Sophie Taeuber-Arp, for instance, could be seen in the section devoted to deceased famous artists. Another was Marlow Moss, the only artist known to have inspired Piet Mondrian to break new ground through her introduction of double lines. As was Nicolaas Warb (Fine Warburg), whose organic abstractions elicited high praise from Michel Seuphor, one of the leading art critics of his day, and were collected by French artists and critics such as Michel Ragon. At the same time, however, female artists often talked about how difficult it was for them to gain a foothold in the male-dominated art world. Thus, when the Amsterdam-born Fine Warburg adopted the male pseudonym Nicolaas Warb during the Second World War, it wasn’t merely because her own name sounded German, which was obviously far from convenient for anyone in Paris at the time, but also because it was likely to make local art critics take her more seriously. Hémon’s letters to Picasso further testify to the difficulties faced by female artists, for whom networking was therefore not merely an afterthought.
A NEW WORLD
Events in the Parisian art scene came to a virtual standstill during the war. And in the aftermath of this global calamity, which saw the Cold War break out between the United States and the Soviet Union and countries in different regions set about freeing themselves from colonial rule and gaining independence, a process that sometimes led to violent struggle, the world found itself facing a fundamental question: How to begin anew? The newly regained freedoms fueled the need for artistic renewal, for innovation reflecting this new world. From the pre-war French nationalist perspective, geometric abstract art was cold, foreign, and suspect. But fans of nonrepresentational art, such as the aforementioned Fredo Sidès, rejected this line of thought and welcomed the influx of foreign abstract artists into Paris. Younger artists began trying to free themselves from the conventions of realism, which had been dominant in the interwar period and throughout the war, but was now “tainted” by nationalism and Nazi ideology. It was telling, for instance, that the Stedelijk’s Abstracte Kunst exhibition in 1938, intended as counterpoint to and protest of Hitler’s Entartete Kunst (Degenerate Art) exhibition in Munich the year before, had attracted few visitors. But that was then. Now, in 1945, younger artists sought to return to the internationalism and social utopian ideals of artists of the 1910s and 1920s, in the hope of ushering in a more harmonious society. Among the ideas these artists found compelling was that of “absolute art,” a term that had been used to describe music since the 19th century.
In their early writings and later at the Bauhaus, Wassily Kandinsky and Paul Klee had advocated the autonomy of the means of creating imagery, line, color and composition, independent of representation by seeking an analogy with music, which was considered absolute art and universally intelligible, universally valid. And in the 1950s, ideas like these were also promoted in the Netherlands by people like Paul Citroen, Paul Schuitema and Willem Schrofer at the Royal Academy of Art in The Hague. These artists and art educators encouraged students to study the writings of Kandinsky and the Bauhausbücher essays by Mondrian, Theo van Doesburg, Paul Klee and László Moholy Nagy. The prevailing interest in music was closely tied to a preoccupation with the cosmic laws that govern and underpin the visible manifestations of nature. In this regard, art theorists were taking their lead from the Greek philosopher Pythagoras, who presented the cosmos as a harmonious arrangement of bodies to be expressed in numerical proportions based on the intervals of a musical scale. This theory, the result of studies taken in the Middle East, precipitated an interest in mathematics among a number of artists. The idea of a “synthesis of the arts” was also very much in vogue and expressed in, among other things, a preference for a synthesis of calculation and intuition, again by analogous reference to the creation of musical compositions. In the 1950s, even artists who were less metaphysically inclined operated on the assumption that visible reality was based on a systematic order that could be expressed in geometric forms, and as a result employed reflection, repetition and rotation similarly to their more metaphysically inclined colleagues. Consequently, abstract art from that period often featured a combination of curved and rectilinear elements.
Later in life, Hémon offered a succinct summary of her thoughts on line, color and abstraction in relation to music during a radio interview:
"I use color merely to indicate where a line begins and ends. [...] In other words, the colors in my paintings are for lines and planes [...] for differentiation purposes only. [...] I regard abstraction the way a composer would [...] a composer with an idea; the idea comes from within, is channeled from the mind. It’s one-way traffic. But figuratively, everything figuratively [...] is easier to understand, you observe something somewhere and take it in, from the outside, and give it back. That’s two-way traffic. [...] real abstract painting is therefore only what arises from within, what wasn’t yet visible and what you make visible."
SEDJE HÉMON Pensées/Reflections, 1957, oil on canvas, 54.5 x 84.5 cm Stedelijk Museum Amsterdam © Sedje Hémon Foundation Photo: © Marjon Gemmeke
SHARED BELIEFS: HÉMON, JAFFÉ, SANDBERG
Sedje Hémon was among only a handful of Holocaust victims who managed to survive captivity in four separate concentration camps and had also fought in the resistance. According to a reliable source, she likely received help from Queen Juliana during her period of recovery through Stichting 1940-1945, a foundation set up to lend support to Second World War resistance members. The question now is, once the war was over, what information did she have access to regarding developments in modern art? Did she go through magazines on contemporary art such as Art d’aujourd’hui (Art Today), the first magazine devoted entirely to geometric and organic abstract art, which launched in 1949 and was renamed Aujourd’hui: Art et Architecture in 1955? During her lengthy convalescence, in which she tried in vain to resume her career as a violinist and took up abstract drawing and painting in the South of France, she says she immersed herself not only in music theory but also in painting, architecture and dance. When painting, she would recall the abstract patterns she drew in her youth: “[…] when I was about three or four, I began drawing nothing but dots and lines, and had no inclination to draw dolls or trees [...] I never felt like drawing anything figurative.” She seems to have had a strong impulse to learn and discover things intuitively from an early age. While convalescing, did she pay visits to museums of modern art in her hometown of The Hague or in Amsterdam? Later in life, people like Jaffé supported her in the development of her own theory of art.
Hans Jaffé fled Germany in 1933, at the age of 18, as Nazism was on the rise, arriving in Amsterdam, where he had an uncle, to study art history. He worked as a volunteer at the Gemeentelijke Musea (the organization of Amsterdam’s municipal museums, under which the Stedelijk operated) from 1935 to 1941. Jaffé was initially drawn to the work of artists like Vincent van Gogh and to expressionist art, but found himself increasingly entranced by the beliefs and principles of De Stijl movement, on which he would go on to obtain a doctorate. Outside the museum, he maintained contact with artists from both schools, such as fellow exiles Max Beckmann and Friedrich Vordemberge-Gildewart, exponents of expressionism and geometric abstract art, respectively. Sandberg’s artistic development had run in the opposite direction. Before the war, he’d been largely influenced by De Stijl, Nieuwe Bouwen and the Bauhaus movements’ “reductionist” approaches to art, design and architecture, and only later discovered an affinity with expressionism, partly as a result of the war and the founding of the CoBrA movement. The two men’s opposing influences made for a highly complementary working relationship, at least initially. When Jaffé joined the Stedelijk as a curator in 1946, he, like Sandberg, had progressive, leftist beliefs about the possibility of advancing society.
"Both were of the view that art had a pioneering role to play in the betterment of society. In the policies they produced as deputy director and director of the Stedelijk, they prioritized expressionist and constructivist art alternately."
Up until the early 1950s, they both believed in a linear model in which waves from both schools succeeded each other in a dialectical development toward a future goal: a universal form of abstract art. After this period, they began making a more ahistorical distinction between art that seeks order and beauty, or “supra-personal” harmony, and art that seeks to express individual freedom and originality.
In Sedje Hémon’s work, they found and were able to enjoy both. Jaffé often wrote about the intuitive and spontaneous nature of Hémon’s oeuvre as well as its mathematical qualities. Her closed, angular and curved forms in combination with some of her titles suggested freedom and personal expression, while the reflections, repetitions, rotations, novel titles, and her belief that her visual work actually constituted music, corresponded to the idea of a supra-personal, cosmic order. About this, Hémon herself said, among other things: “Without deliberate intention, I used proportions that correspond to certain intervals, harmonies and consonances in music.” And, “I still felt as though I had my legs in different camps, one in music the other in painting, and I couldn’t make headway with both legs simultaneously.” Then in 1964, she had a breakthrough: “It came to me out of the blue: my paintings were music. I promptly began working at a furious pace, converting my drawings into musical notation so that I could hear them.” Her book Hémon’s integratie der kunsten includes a contribution by Jaffé, in which he writes: “the basis of this relationship was already foretold in a statement by Gustave Flaubert in 1851: ‘art will become something half-way between algebra and music.’”
Cover of Sedje Hémon’s book, Integratie der kunsten (The Hague: Hémon—Artinteraction, 1996) © Sedje Hémon Foundation
Jaffé’s advice to Hémon to pursue her insights intuitively and avoid reading what others had written about the relationship between visual art and music corresponds neatly with the idea of genius, which has a long tradition in art and ties in with his politically progressive beliefs. Artists such as Gustave Courbet, Jean-François Millet, Van Gogh, and George Hendrik Breitner, and later Constant in his role as spokesperson for the CoBrA movement, were all influenced by the French historian Jules Michelet’s thoughts on genius. In his book Le peuple (1846), Michelet described genius as a “folk” phenomenon. He argued that genius has a strong preference for children and “simple-minded people” who do not speak in the conventional language and are therefore all the more original, imaginative and gifted with an exceptional talent for spotting unexpected connections between disparate things. But these qualities would always only manifest themselves partially in the collective. Only in the genius were they to be found in perfect form. Sandberg also believed in this conception of genius. He spoke several times of the “genius” Rietveld, “who had such a direct, almost primitive approach to design that everything he touched was imbued with his sense of beauty.” And: “Rietveld was [...] very straightforward, like all geniuses, very direct, no detours.” For both Jaffé, and Sandberg, Hémon’s unconventional interpretation of her linocuts and paintings as spatial musical notes was perhaps a sign of genius. This assumption appears to be supported by the fact that art historian Elmyra van Dooren, a former assistant to Hémon and a former student of Jaffé, is currently working on a book about genius, in which she reserves an important place for Hémon. That being said, in Hémon’s integratie der kunsten Hémon did ground her ideas in art history and philosophy, partly on the basis of Jaffé’s writings.
The Stedelijk’s acquisition of two of Hémon’s paintings and Sandberg and Jaffé’s decisions to accept the twenty donated linocuts were likely based not merely on the works’ artistic merits but also on the pair’s shared ideas about Hémon’s artistry and the nature and meaning of her work. Conversely, Sedje Hémon may have felt that Jaffé had understood what her work was about even before she had, and she possibly also had reason to assume that Sandberg viewed her work favorably. The Dutch press, for its part, admired her persona, life history, and working practices, but were less convinced of her work’s artistic qualities. The critics, who apparently entertained more conventional ideas about painterliness and an artist’s signature, may have associated her compositions and austere executions with the decorative practices of mirroring, repetition, and rotation, and perhaps also with what they saw as a somewhat facile play with foreground and background. But to contemporary viewers, accustomed to stylistic pluralism and hard edges, the subtleties and painterly elements of her work are more readily appreciated. Jaffé and Sandberg appear to have been more open-minded in their appreciation of her work than the Dutch critics of the time.
Some of Hémon’s works have a surprisingly contemporary feel. Take paintings with unconventional formats such as Comme si le coin recule (As if the Corner Draws Back), 1958), in which the painting appears quite sculptural and folding inwards, or a sculpture like Marchons autour (Let’s walk around, 1956), which was exhibited in Brussels in 1960 as an arrangement of a somewhat shiny hard-edged sculpture on a pedestal with fabric drapery and against a backdrop composed of strips of fabric. Her early interest in the possibilities offered by computer applications is likewise echoed in their use in artistic practice today. At the same time, the relationship with music links her work and artistry to earlier practices and artists originating in different parts of the world, as the current exhibition at the Stedelijk demonstrates.
Installation view of the exhibition Sedje Hémon, Imran Mir, Abdias Nascimento: Abstracting Parables, Stedelijk Museum Amsterdam, 2022, with, above, Sedje Hémon, Comme si le coin recule / If the Corner Draws Back, 1958. © Stedelijk Museum Amsterdam / Photo: Peter Tijhuis.
About the Authors
Maurice Rummens is a member of the Research staff at the Stedelijk Museum Amsterdam. He holds a PhD in Art History from the University of Amsterdam and his writing has been published in, among other, Jong Holland, Kunstschrift, The Burlington Magazine, and in publications from the Open University. He co-curated the exhibitions Roger Bissière: ‘La cathédrale’, Tapestry (2000), Ernst Ludwig Kirchner. Tahiti in the Alps, 1918-1928 (2001), The Oasis of Matisse (2015), and curated Chagall, Picasso, Mondrian, and Others: Migrant Artists in Paris (2019-2020) at the Stedelijk Museum.
Claire van Els is an art historian and curator at the Stedelijk Museum Amsterdam. She assisted sonsbeek20→24 in the making of the exhibition Sedje Hémon. Imran Mir. Abdias Nascimento. Abstracting Parables at the Stedelijk.
Gwen Parry is Senior Editor at Stedelijk Museum Amsterdam. She studied art history and political science, the intersections of which remain the focus of her practice as editor, writer, and publisher.
 This text was written by Maurice Rummens, with the assistance of Claire van Els, edited by Gwen Parry, and translated from Dutch by Siji Jabbar, with research support by Carlos Zepeda. Special thanks to Elmyra van Dooren and Peter Wapperom, president and vice president of the Sedje Hémon Foundation respectively, who were unstinting in their assistance to us in writing this article. Many thanks to Carlos Zepeda as well for his research on source material.
 Diane V. Silverthorne, ed., Music, Art and Performance from Liszt to Riot Grrrl: The Musicalization of Art (New York: Bloomsbury Academic, 2018); Peter Vergo, The Music of Painting: Music, Modernism and the Visual Arts from the romantics to John Cage (London: Phaidon Press, 2010); Maurice Tuchman, “Hidden Meanings in Abstract Art,” in: exh. cat. The Spiritual in Art: Abstract Paintings 1890-1985, Los Angeles, Chicago, The Hague (Los Angeles County Museum of Art, Museum of Contemporary Art, Haags Gemeentemuseum), Los Angeles / New York 1986, pp. 17-62; Evert van Uitert, “Beeldende kunst en muziek,” in: exh. cat. Kunstenaren der idee. Symbolistische tendenzen in Nederland, ca. 1880-1930 (The Hague: Haags Gemeentemuseum, 1978), pp. 67-75.
 See Sedje Hémon, Hémon’s integratie der kunsten. Studie over de relatie schilderkunst en muziek, met foto’s van Hémon schilderijen, naast schilderkunst en muziekvoorbeelden. Historical Reflections Prof. Dr. H.L.C. Jaffé (The Hague: Hémon—Artinteraction, 1996), pp. 245-267.
 “In 1960, Prof. Jaffé gave me some practical advice that has always stayed with me. He ‘forbade’ me to consult anything written by other artists or critics. He also refused to give me any information about existing ideas regarding the integration of the arts. He was convinced that doing so would lead me astray and that I would thereby fail to achieve my goal. And while I didn’t fully appreciate the significance of his advice at the time, I abided by it until 1992, after which I began looking into what others had said on the subject.” See Sedje Hémon Foundation website. [last accessed June 24, 2022].
 Hémon’s integratie der kunsten, op. cit. (note 3), p. 61.
 From April 1944 in Birkenau and Auschwitz, from January 1945 Ravensbrück and Neustadt-Glewe.
 Exh. cat. 10e Salon des Réalités Nouvelles (Paris: Musée des Beaux-Arts de la Ville de Paris, 1955), Cat. Nos. 350-357; “Abattement” in Hémon’s integratie der kunsten, p. 323, supplemented by: (à la mémoire de Mons. J. Klippus Sr.) (in memory of Mr J. Klippus Sr.); Jean des Vignes Rouges et al., Réalités Nouvelles 1955, no. 9 (Paris: Salon des Réalités Nouvelles, 1955), p. 69.
 Anon., “Sedje Hémon: in Parijs ontdekt,” Het Vaderland, August 5, 1955.
 The Stedelijk library’s copy of the catalog has two “v” before her name, one written in ink and one in pencil, as is the case with several other artists. Others have one “v” or a “v-” They appear to be value judgments. Might this have been Sandberg’s or Jaffé’s copy?
 Domitille d’Orgeval, “Origines 1946-1970” in Artension n°14, L’abstraction Aujourd’hui, Hors-série, Paris, 2014, pp. 68-69; id. Salon des réalités nouvelles: les années décisives, de ses origines (1939) à son avènement (1946-1948), Thèse sous la direction de Serge Lemoine (Paris: Université Paris IV-
Sorbonne, 2007); Dominique Viéville, Alain Quagebeur, Jean Étienne Grislain, Réalités nouvelles: 1946-1956: Anthologie de Henry L’hotellier (Calais: Musée des Beaux-Arts de Calais, 1980).
 Henry Valensi wrote the introduction to the catalog of Hémon’s exhibition at Galerie Colette Allendy in 1956. Here he does not as yet refer to her as a “musicalist,” given her status as a newcomer to Paris, despite presenting her work under that umbrella at the previous year’s edition of the Salon des Réalités Nouvelles, “Mr. Henry Valensi, de Paris, a répondu de fort aimable façon à une prière de Mme Hémon,” in: exh. cat. Mme Sedje Hémon. Peintre hollandaise (abstrait) (Paris: Galerie College Allendy, 1956). The “Introduction” also appears in Hémon’s integratie der kunsten, pp. 77-78.
 See, for instance, Thomas Schmutz (ed.), Sophie Taeuber-Arp: Heute ist Morgen (Zurich: Scheidegger & Spiess, 2014); Ulrike Groos, Konkrete Künstlerinnen: zwischen System & Intuition (Cologne: Wienand, 2021); Christine Macel and Karolina Ziebinska-Lewandowska, eds., Women in Abstraction (London: Thames & Hudson, 2021).
 See, for instance, Sabine Schaschl, ed., Marlow Moss: a Forgotten Maverick (Berlin: Hatje Cantz, 2017); Lucy Howarth, Marlow Moss (Eiderdown: E-books, 2019).
 See Marianne Bierenbroodspot, Nicolaas Warb (1906-1957) en haar interpretatie van de kleurenleer van Goethe: een aanzet tot een catalogue raisonné, unpublished doctoral thesis (Amsterdam: Vrije Universiteit, 2007).
 See Archives National de France, under Fonds Pablo Picasso C 1-C 177, Correspondence received by Pablo Picasso. There are 8 pieces by Sedje Hémon between 1955-1964, listed under Classeur 63. [last accessed June 24, 2022]. Courtesy of Carlos Zepeda.
 See for instance, Serge Guilbaut, Lost, Loose, and Loved. Foreign Artsits in Paris, 1944-1968, exh. cat. (Madrid: Museo Nacional Centro de Arte Reina Sofia, 2018); Fanny Drugeon, Paris Cosmopolite. Artistes étrangers dans la capitale française, 1945-1989. Éléments d’une recherche en cours. (Foreign Artists in Paris and their Careers, 1945-1989. Elements of Ongoing Research), January 2015, parcours_1945-1989_Contextes_acteurs_processus. [last accessed June 24, 2022].
See, for instance, Romy Golan, Modernity and Nostalgia: Art and Politics in France Between the Wars, (New Haven: Yale University Press, 1955); Kenneth E. Silver, L’Esprit de Corps: the Art of the Parisian Avant-Garde and the First World War, 1914-1925 (New Jersey/London: Princeton University Press, Thames & Hudson, 1989); Christian Derouet, “Kandinsky, ‘triumvir’ de l’exposition du Jeu de Paume en 1937,” in exh. cat. Paris 1937-Paris 1957, Créations en France (Paris: Centre Geroges Pompidou, 1981), pp. 103-108; Catherine Amidon, “Indépendants” et “modernisme démodé.” Les expositions à Paris en 1937’, in: Andrzej Turowski, ed., Les fragments… (1). Arts et artistes autour de C. Zervos, Dijon 1997, pp. 99-119.
 See Jonneke Fritz-Jobse, Frans van Burkom, Carel Blotkamp, Een nieuwe synthese: geometrisch abstracte kunst in Nederland 1945-1960 (The Hague: SDU Uitgevers/Publishers, 1988).
 Transcript of a radio interview, Radio 4 Tros, September 23, 1997, Sedje Hémon Foundation archive
 Courtesy of Peter Wapperom, vice president of the Sedje Hémon Foundation, at whose grandparents’ house in Amsterdam Sedje Hémon was in hiding during the war.Juliana was Queen of the Netherlands from 1948 to 1980—which also included Suriname until 1975 and the Dutch Antilles until 2010. She lived in Paleis Soestdijk in the province of Utrecht.
 “I was in the resistance, and was arrested at the end of April 1944, and spent three years (1945 to 1948) recovering at a series of hospitals, where I put myself to work as soon as I arrived. I studied music and music theory, as well as painting, architecture, movement and dance, all of which struck me as relevant. And because they did, my studies expanded in all directions, to the extent that I had to devote each day until lights out to what I was doing. And I did this at every hospital.” Source: transcript of a radio interview on Radio 4 Tros, 23-09-1997, Sedje Hémon Foundation archive.
 Transcript of a radio interview, Radio 4 Tros, September 23, 1997, Sedje Hémon Foundation archive.
 See Caroline Roodenburg-Schadd, Expressie en ordening: het verzamelbeleid van Willem Sandberg en Hans Jaffé in het Stedelijk Museum in Amsterdam, 1945-1963 (Amsterdam/Rotterdam: Stedelijk Museum Amsterdam/NAI Uitgevers Rotterdam, 2004).
 Hémon’s integratie der kunsten, pp. 10, 12, 13, 16, 18, 37, 53, 54, 59, 60, etc.
 Floor de Booys, “Muziek voor het oog,” Haagsche Courant, 22 January 1997.
 “…que l’art sera quelque chose qui tiendra le milieu entre l’algèbre et la musique.” H.L.C. Jaffé, “Eerste uitvoerbare resultaten van de integratie schilderkunst/muziek,” in: Hémon’s integratie der kunsten, p. 35.
 See J.A. Emmens and E. de Jongh, “De kunsttheorie van Cobra, 1848-1948,” Simiolus: kunsthistorisch tijdschrift 1 (1966-1967), pp. 51-64.
 Ank Leeuw Marcar, Willem Sandberg, portret van een kunstenaar (Amsterdam: Meulenhoff, 1981),
See Hémon’s integratie der kunsten, pp. 4, 101-103, 116, 180