By Ivan Zetina

It is incontrovertible that Julio Estrada is a vigorous and radical figure in music creation. His approach combines the formal sciences with philosophy of art, as well as more subjective inputs such as intuition and imagination.¹ Estrada took part in some of the most avant-garde trends of the twentieth century. His intransigence in these pursuits entangled him in controversies related to traditional music theory, the role of cultural institutions in artistic creation, and his aesthetic opposition to certain paradigmatic figures in composition.

Estrada has fought for intellectual and artistic freedom, questioning any type of conformism or dogmatism in his creative process. For these reasons, it is difficult to situate him in an aesthetic within contemporary music. From the outset of his career, he has been careful not to reduce his aesthetic commitments to any one mainstream movement. He produces his work on the principles of research and creation, which has enabled him to find innovative solutions to challenges in creating music.

His activity goes beyond composing. He also performs — notably as a singer of his own work — and has taught with dedication for more than four decades at the Universidad Nacional Autónoma de México.² He has also written and overseen academic publications on subjects as varied as the pre-Hispanic and modern musical history of Mexico, the connections between music, mathematics, and technological innovation in music theory, and the notion of the imagination in music — a key aspect of his own work as a composer.

Estrada has two forces driving his work: objective scientific research and subjective experience from his personal life. His aesthetic path split in five directions, each representing a phase in his musical exploration. Overall, his work has evolved through a combination of formal concerns supported by scientific research and subjective concerns such as imagination and creativity.

From silence to Cantos: Finding his voice

Before finding his own creative voice, Estrada went through a period of near silence between 1959 and 1973, punctuated by a few creative attempts. During this transitional phase, he distanced himself from outside influences and developed his own approach to creation.

He met Julián Orbón (1925-1991), who taught him composition from 1960 to 1962 at the Conservatorio Nacional de Música (Mexico). Orbón guided him in a key realization: to learn to reveal himself in every influence and then find a way to integrate this into his music, so as to create music through his own unique solutions.

Estrada’s starting point for creation is to appropriate the influences that mark him, then to go beyond them and challenge the aesthetic ideas of other artists.³ Before finding his own path, he went through a period of exploration, gradually distancing himself from the popular styles of the time. These influences were a necessary starting point for his personal journey.

Tres instantes, for cello and piano (1966), is an example showing the influence of total serialism and particularly Karlheinz Stockhausen. Memorias para el teclado (1971) both appropriates and challenges minimalism by replacing the principle of repetition with one of non-repetition, through constantly varying the repeated content.⁴ Finally, taking up John Cage’s idea of silence, Estrada created Solo para uno (1972), offering the listener, whether musician or music lover, a series of texts that encourage intimate forms of listening.

The period, when Estrada began to envisage autonomy from aesthetic trends, corresponds to the genesis of the Cantos cycle, comprising six works. Canto mnémico, Fugue in 4 Dimensions, for string quartet (1973), stems from his study of finite groups, in which he elaborated a system of continuous transformation of subject and countersubject. Canto tejido, for piano (1974), consists of networks of isolated pitches that generate meloharmonic textures. Canto oculto, for violin (1977), develops original performance techniques. Canto alterno, for cello (1978), and Arrullo, Canto ad libitum, for voice and instrument(s) (1979), use a structure of labyrinthine networks. These pieces are the aesthetic results of his extensive theoretical and practical research, particularly in relation to systems and finite group theory.⁵ In such mathematical theories, Estrada found ways to question traditional musical systems, understand them, and integrate them into a wider universe.⁶

The birth of his children inspired other works from this period. Melódica, mécano musical (1974) is a children’s game composed after the birth of his son Julián. Its purpose was to be an educational tool for teaching musical creation. With the birth of his second son, Amadeo, he composed Canto naciente, for brass octet (1975), which dramatically recreates the space surrounding the child in the womb.⁷ With this key work of this period, he created three-dimensional melodic and harmonic spatialization by distributing the musicians across the eight vertices of a cube. The experimentation stemming from this work explores interval classes and their minimal distances, forming the basis of Teoría d1, which minimizes the combinatorial potential of scales, including the twelve-tone scale, reducing it to seventy-seven identities or vertical aggregates.

The yuunohui and “continuous macro-timbre”

Estrada’s reflections on “the continuum” began when he worked on eua’on (1980), an electroacoustic piece created using UPIC (Unité Polyagogique Informatique CÉMAMU), the sound-writing computer system designed by Iannis Xenakis and developed under his direction at the Centre d’Études de Mathématique et d’Automatique Musicales (CÉMAMU). With UPIC, Estrada could graphically represent his musical ideas with greater precision and freedom. Initially dissatisfied with the resulting electronic sound, he later wrote an orchestral version of the work, entitled eua’on’ome (1995), which manifests a development in his handling of individual and collective instrumental timbres. Eua’on marked the start of a new period characterized by close links with research into the continuum and musical perception.

This was the pivotal moment when Estrada departed radically from the European musical tradition and rejected the term “composer,” which he found academic and submissive, preferring “creator.” In Estrada’s view, being a “composer” limits creativity to simply arranging or assembling musical components through combination. In contrast, a “creator” has a holistic ability to invent new materials or create something entirely different from traditional works of art.

His experimentation with the continuum is rooted in Henry Cowell’s theories on the connection between pitch and duration.⁸ For Estrada, the continuum is the physical result of the fusion of rhythm and sound, similar to Einstein’s concept of space-time. Using this approach, he undertook a chrono-acoustic analysis of a wide range of physical components, including rhythm (pulse, attack, micro-duration, and vibrato), sound (pitch, dynamics, and color), space (width, depth, and length), and the nebulous concepts of inharmonic sounds, pressure in emission, and rhythmic disorder. He calls this vast synthesis of components “macro-timbre,” which informs the new way of listening he develops in his instrumental and vocal music.

His “continuous macro-timbre” writing was first concentrated in the rhythm-sound-space synthesis of eolo’oolin, for six ambulatory percussionists in a pentagon (1981-1998), then in ishin’ioni, for ambulatory string quartet in a hexagon (1984-1990). Between these two works, Estrada initiated the yuunohui cycle (1983-2019), meaning “fresh land, without stones” in Zapotec (an Amerindian language group from the state of Oaxaca). The cycle comprises seven versions, all consisting of similar modules and preceded by the name yuunohui: strings (‘se, ‘ome, ‘yei, ‘nahui), keyboard (tlapoa), noisemaker (‘wah), wind (‘éhécatl*), and voice (‘sa). Modules are independent pieces that can interact through a complex system of juxtaposed and/or sequential connections (networks). Thanks to networks between the modules, Ensemble ’yuunohui allows all versions to be superimposed: from duets to groups of more than seven performers.

On a formal level, he explores open forms by using devices such as networks and modules. These two elements underlie the macrostructures of his opera Murmullos del paramo (1992-2006). From the initial module of this opera, Estrado extracted mictlan (1992), miqi’nahual for double bass (1994), and miqi’cihuatl for female voice (2002).

A “multi-opera”

Estrada based his opera Murmullos del páramo (Murmurs of the Paramo; 1992-2006) on the novel Pedro Páramo by the Mexican writer Juan Rulfo. In his title, Estrada uses the term “páramo” not in reference to the proper name in the novel’s title, but in the sense of “flat, arid, parched, and generally elevated land.”

The first version of the opera was Doloritas (1992), a radio opera. The final version (2006) features seven voices, five instruments (double bass, noisemaker, shō, guitar, and trombone), butoh dance, and three-dimensional electroacoustic spatialization by the Experimental-Studio in Freiburg. The structure is labyrinthine in its use of seven modules: mictlan (female voice, noisemaker, and double bass), Hum (vocal quintet), mictlan’ome (soprano, contralto, noisemaker, double bass, shō, trombone), Caja con trenzas (guitar), Portrait of Páramo (trombone), Matlapoa (shō), and Fósiles resonantes (five voices and five instruments).

Estrada’s “multi-opera” is the incarnation and synthesis of his long experience in musical creation and experimentation. It is an essential work when defining his aesthetic and is intimately linked to key moments in his life. Estrada’s writing of Murmullos del páramo accompanied the painful period of the illness and death of his wife, Velia Nieto. According to Estrada, his deepest intention in creating this opera was to preserve his wife’s voice, so he would never forget her.

He conceived the work along two aesthetic lines. The first is synesthesia, applied to the stage direction by integrating smell, spatialization, set design, body paint, and costumes, as well as sound in all its dimensions. The second is the decomposition of elements of traditional opera. Decomposition is on display within the text the actors recite (sourced from the novel’s narration); in the voice used for affect, rather than discourse; through symbolism, as certain characters are represented by instruments; through the sounds of the environment described in Rulfo’s novel; and in the dancer’s movements, which are independent of the other elements.

Estrada wrote the opera’s libretto himself, sourcing materials from the book. These texts also led him to use Mexican popular music within the score. His preoccupation with musical cultural identity is evident in the opera, as he breaks down and integrates folk melodies into his sound universe. His is a universe that recognizes no boundaries between musical genres, nor between music and the noises of the environment he represents.

Time for introspection

Over the past two decades, Estrada’s work has oscillated between two poles of musical thought. First is the pursuit of creative and interpretative freedom through controlled improvisation, in what he calls “in vivo creation.” Estrada would define this notion as follows:

The process I follow in creating in vivo consists in generating music without writing, solely with the clear capture of the image that occurs in reality or in the imagination. In this way, memory and instrumental mastery weigh less, while the degree of perception, synesthesia, and creative intuition increase, seeking by their own means the continuation of the original impulse.⁹

After Murmullos del páramo, works that follow this method are Simultáneas a 3, for three cellos (2004); Búsica, for voice and cello (2004); Quotidianus: Polvo eres, for voice and string quartet (2006); Bajo el volcán: In memoriam Stefano Scodanibbio, for double-bass ensemble (2012); ni die saa, for five instruments (2013); and Trompos a la uña, for fifteen drums (2017).

He also uses a variation of this method, employing literature to guide the performer’s and listener’s inner listening and imagination (e.g., a work in progress known by the name Velia: Creo en lo que creo, A Velia, or other titles). He aims to stimulate the listener’s ability to create intimate sound worlds through a literary form that privileges sound images from the creator’s imagination. This variant has its roots in the synesthesia explored in his multi-opera.¹⁰ Since 2008, the year of his wife’s death, Estrada has been following an intimate creative process that takes up in vivo creation to explore the musical materials of a novel-opera. In this work, the reader, guided by an intimate listening process, interprets the musical meaning of the words, taking us back to Estrada’s very first creative period, with the aforementioned Solo para uno.

The second pole of Estrada’s recent music is an evolution of his rigorous writing system and initial research. In the 2010s, he revived old writing procedures but with less determinism, as in the case of yuunohui’ehecatl, for woodwinds and/or brass (2010), and yuunohui’sa, for voice (2019). In doing so, he open up new perspectives for the performer. Through a continuous elaboration of the musical material, he aims for an increasingly permissive mode of expression, leaving the performer more freedom.

On the academic front at the Universidad Nacional Autónoma de México, Estrada continues to reflect on how the arts are taught. Through his lectures, colloquia, and seminars, he has developed an original approach to teaching the arts based on multidisciplinarity and trans-disciplinarity. He thus explores concepts that cross the boundaries of artistic disciplines, such as perception, imagination, design, representation, rhythm, and proportion. His artistic ideal is to emancipate the subject, as well as to search for singular beauty elevated to the same level as scientific thought.¹¹

In 2016, when Estrada received the Medalla Bellas Artes, he gave a speech entitled “A destiny for research-creation in art,” where he aimed to refresh ideas about art, the artist’s role in society, and the academic structures surrounding art.¹² Estrada is opposed to arts that restrict the creator’s pursuit of freedom. He suggests that the twenty-first century should move toward freeing art as an autonomous realm that is as essential and esteemed as the life sciences, abstract sciences, and social sciences. Art is not truly legitimate unless it can express feelings and emotion.

Similarly, he addresses the issue of subjectivity and objectivity in art, arguing that metaphysical metaphor and scientific analogy are essential for understanding both the imagination and external reality. The artist observes the outside world and feels the need for a sensitive mechanism to translate and transmit this perception as faithfully as possible. For Estrada, creation consists in building this device by using scientific tools and delving into his own imagination.

All this reflection leads to the concept of “research-creation,” which highlights the pedagogical and ethical dimension of being an artist. Estrada’s aim is to enhance talent through artistic creation informed by scientific research. For him, talent is not an innate quality, as Hegel asserted, but a capacity that develops. The artist’s teaching activities, seen as “an indispensable exercise in the creative renewal of his environment,”¹³ is as integral to his moral character as is his creative process. Thus, the artist has two key social roles: passing on knowledge and skills related to art and, though indirectly evoked, emancipating others and himself through pedagogy that targets the personal.¹⁴

As for the social structures that currently underpin the learning of art, Estrada favors the university over what he calls the “academy,” a concept originating from avant-garde art to refer to conservatories. According to Estrada, making the transition from a conservative structure to a self-renewing structure, that is, from the academy to the university, means eliminating pre-established aesthetic criteria and opening up the disciplines of art to the hard sciences, engineering, and human and social sciences. Estrada’s educational influence is extensive, through his courses in Mexico, the Americas, Europe, and Asia, where he has disseminated his theories and methods of analyzing the creative imagination. His role as head of the Musical Creation Laboratory at the Faculty of Music (Universidad Nacional Autónoma de México) will be decisive in forming several generations of creator-researchers such as Germán Romero, Víctor Adán, Mauricio García de la Torre, Eduardo Aguilar, and Iván Adriano.

Overall, this most recent phase of Estrada’s journey seems directed toward a horizon of deep introspection. Poetically, he favors silence or the almost silent sigh, invoking happy solitude and contemplation. His stance is of someone who chooses to listen intently to both the external and internal worlds. To achieve this, Estrada draws on the perennial characteristics of his thinking — creativity and rigor, freedom and methodology — which he has pursued since the beginning, to achieve the highest degree of artistic intimacy.

Translated from the French by Chrisoula Petridis

^{1. Velia NIETO, Recherche-création dans l’œuvre de Julio Estrada, volumes 1 and 2, Université de Paris VIII, Paris, 1999, 511 p. ↩}

^{2. Julio ESTRADA, “El futuro del arte Universitario,” Memoria, La UNAM y el futuro, Foro conmemorativo 20.20, 2015, pp. 239‑246. ↩}

^{3. Iván Adriano ZETINA, “Entrevista con Julio Estrada: En torno a su obra y pensamiento musical,” 2 July 2018, personal archive. ↩}

^{4. Ibid. ↩}

^{5. Ibid. ↩}

^{6. Ibid. ↩}

^{7. Estrada also believes that rhythmic sound can faithfully represent physical states of matter such as liquids, solids, and magma. ↩}

^{8. Henry COWELL, New Musical Resources, Cambridge University Press, 1996, 177 p. ↩}

^{9. Julio ESTRADA, Boîte avec tresses, Juliusedimus, 2003. ↩}

^{10. Ibid. ↩}

^{11. Iván Adriano ZETINA, “Julio Estrada et la figure de l’artiste-chercheur,” CRAL/EHESS Paris, 18 October 2019, p. 13. ↩}

^{12. Julio ESTRADA, Un destino para la investigación-creación en Arte, Mexico: Institut National de Beaux-Arts, 2016, p. 1. ↩}

^{13. Ibid., p. 4. ↩}

^{14. Julio ESTRADA, “Théorie de la composition: Discontinuum-continuum,” PhD thesis, Université de Strasbourg II, Strasbourg, France, 1994, 500 p. ↩}

© Ircam-Centre Pompidou, 2020

• Solo (excluding voice)
  • Suite for keyboard (1959-1960), 4 mn about , juliusedimus
  • Canto tejido for piano (1974), 7 mn, juliusedimus
  • Canto oculto for violin (1977), 7 mn, juliusedimus
  • Canto alterno for cello (1978), 8 mn, juliusedimus
  • Talla del tiempo for keyboard (1979), 6 mn
  • yuunohui’yei for cello (1983), 11 mn, Salabert
  • yuunohui’nahui for double bass (1988), 11 mn, juliusedimus
  • yuunohui’se for violin (1989), 11 mn, Salabert
  • yuunohui’ome for viola (1992), 11 mn, juliusedimus
  • miqi’nahual for double bass (1994), 10 mn, juliusedimus
  • yuunohui’tlapoa for harpsichord, piano or organ (1996-1998), 11 mn, juliusedimus
  • Caja con trenzas for guitar (2018, 2004), 12 mn about , juliusedimus
  • matlapoa for shō (2000-2006), 14 mn about , juliusedimus
  • Rencor vivo for trombone (2002-2006), 15 mn about , juliusedimus
  • Retrato for trombone (2001-2006), juliusedimus
• Chamber music
  • Tres instantes for cello and keyboard (1966, 1983), 3 mn, juliusedimus
  • Memorias para teclado for piano or keyboard with 2 or 4 hands, accordion or keyboard percussion (1971), between 4 mn and 14 mn, juliusedimus
  • Canto mnémico four-dimensional fugue for string quartet (1973, 1983), 7 mn, Salabert
  • Canto naciente octet for three trumpets, two horns, two trombones, tuba (distributed in a cube or hexagon) (1975-1979), 18 mn, juliusedimus
  • stage eolo’oolin for six percussionists distributed in pentagon space (1984-1988), 40 mn, juliusedimus
  • Ishini'ioni for string quartet distributed in the traditional way or in a hexagon (1984-1990), 18 mn, Salabert
  • Simultáneas a 3 for three cellos (2004), 60 mn, juliusedimus
  • Ni die saa for flute, violin, bass clarinet, guitar and noisemaker (2013), 15 mn about , juliusedimus
• Instrumental ensemble music
  • Diario for fifteen strings or string orchestra (1980), 5 mn, Universidad nacional autónoma de México (UNAM)
  • eua’on’ome for symphony orchestra (1995), 10 mn 50 s, Salabert
  • Naufragio for string orchestra (2003), 10 mn, juliusedimus
  • stage Velia : creo en lo que creo for instrumental ensemble (2008)
  • Bajo el volcán for double bass ensemble (2012), 20 mn about , juliusedimus
  • yuunohui’ehecatl for wood and/or brass instruments (2010-2012), 11 mn, juliusedimus
  • Trompos a la uña for fifteen drum sets (2017), 20 mn about , juliusedimus
• Vocal music and instrument(s)
  • elec Doloritas stereo recording of female voice, noisemaker, double bass, sound environments and actors' voices (1992-2004), 57 mn, juliusedimus
  • mictlan for female voice, double bass and noisemaker (1992-2004), 35 mn about , juliusedimus
  • elec Búsica for voice, cello and electronics (2005), 10 mn about , juliusedimus
  • Fósiles resonantes for five voices and instruments (2005-2006), 10 mn about , juliusedimus
  • elec stage Murmullos del páramo opera for two female voices, vocal quintet, trombone, double bass, guitar, sho, recording of sound environments and voice of actors, 3D spatialization (1992-2006), 1 h 40 mn, juliusedimus
  • Quotidianus, polvo eres for voice and string quartet (2006), 12 mn, juliusedimus
• A cappella vocal music
  • Persona graphic score for trio of non-professional voices: male, female or mixed (1969), 15 mn, juliusedimus
  • Solo para uno verbal score (1972), between 60 s and 15 mn, juliusedimus
  • elec Hum’ome for five voices distributed in space and electronics (2002), 12 mn, juliusedimus
  • miqi’cihuatl for soprano (2004), 10 mn, juliusedimus
  • Hum for vocal quintet (2006), 35 mn, juliusedimus
  • yuunohui’sa for voice (2018-2019), 11 mn, juliusedimus
• Electronic music / fixed media / mechanical musical instruments
  • elec eua’on for UPIC electroacoustic system (1981), 7 mn, juliusedimus
• Unspecified instrumentation
  • Solo for any solo instrument or for an ensemble of solo instruments (1969-1970), between 4 mn and 8 mn, juliusedimus
  • Melódica (mecano musical) for one or two melodic instruments (for children) (1974), between 60 s and 15 mn, juliusedimus
  • Arrullo, Canto ad libitum for female voice with or without accompaniment of other instruments (1979), 12 mn, juliusedimus
  • yuunohui’wah for noisemaker (2008), 11 mn, juliusedimus
  • Ensemble yuunohui for different types of instruments (strings, keyboard, noisemaker, winds, vocals) that can be combined (1990-2020), 11 mn, juliusedimus

• 2020
  • Ensemble yuunohui for different types of instruments (strings, keyboard, noisemaker, winds, vocals) that can be combined, 11 mn, juliusedimus
• 2019
  • yuunohui’sa for voice, 11 mn, juliusedimus
• 2017
  • Trompos a la uña for fifteen drum sets, 20 mn about , juliusedimus
• 2013
  • Ni die saa for flute, violin, bass clarinet, guitar and noisemaker, 15 mn about , juliusedimus
• 2012
  • Bajo el volcán for double bass ensemble, 20 mn about , juliusedimus
  • yuunohui’ehecatl for wood and/or brass instruments, 11 mn, juliusedimus
• 2008
  • stage Velia : creo en lo que creo for instrumental ensemble
  • yuunohui’wah for noisemaker, 11 mn, juliusedimus
• 2006
  • Fósiles resonantes for five voices and instruments, 10 mn about , juliusedimus
  • Hum for vocal quintet, 35 mn, juliusedimus
  • elec stage Murmullos del páramo opera for two female voices, vocal quintet, trombone, double bass, guitar, sho, recording of sound environments and voice of actors, 3D spatialization, 1 h 40 mn, juliusedimus
  • Quotidianus, polvo eres for voice and string quartet, 12 mn, juliusedimus
  • Rencor vivo for trombone, 15 mn about , juliusedimus
  • Retrato for trombone, juliusedimus
  • matlapoa for shō, 14 mn about , juliusedimus
• 2005
  • elec Búsica for voice, cello and electronics, 10 mn about , juliusedimus
• 2004
  • Caja con trenzas for guitar, 12 mn about , juliusedimus
  • elec Doloritas stereo recording of female voice, noisemaker, double bass, sound environments and actors' voices, 57 mn, juliusedimus
  • Simultáneas a 3 for three cellos, 60 mn, juliusedimus
  • mictlan for female voice, double bass and noisemaker, 35 mn about , juliusedimus
  • miqi’cihuatl for soprano, 10 mn, juliusedimus
• 2003
  • Naufragio for string orchestra, 10 mn, juliusedimus
• 2002
  • elec Hum’ome for five voices distributed in space and electronics, 12 mn, juliusedimus
• 1998
  • yuunohui’tlapoa for harpsichord, piano or organ, 11 mn, juliusedimus
• 1995
  • eua’on’ome for symphony orchestra, 10 mn 50 s, Salabert
• 1994
  • miqi’nahual for double bass, 10 mn, juliusedimus
• 1992
  • yuunohui’ome for viola, 11 mn, juliusedimus
• 1990
  • Ishini'ioni for string quartet distributed in the traditional way or in a hexagon, 18 mn, Salabert
• 1989
  • yuunohui’se for violin, 11 mn, Salabert
• 1988
  • stage eolo’oolin for six percussionists distributed in pentagon space, 40 mn, juliusedimus
  • yuunohui’nahui for double bass, 11 mn, juliusedimus
• 1983
  • yuunohui’yei for cello, 11 mn, Salabert
• 1981
  • elec eua’on for UPIC electroacoustic system, 7 mn, juliusedimus
• 1980
  • Diario for fifteen strings or string orchestra, 5 mn, Universidad nacional autónoma de México (UNAM)
• 1979
  • Arrullo, Canto ad libitum for female voice with or without accompaniment of other instruments, 12 mn, juliusedimus
  • Canto naciente octet for three trumpets, two horns, two trombones, tuba (distributed in a cube or hexagon), 18 mn, juliusedimus
  • Talla del tiempo for keyboard, 6 mn
• 1978
  • Canto alterno for cello, 8 mn, juliusedimus
• 1977
  • Canto oculto for violin, 7 mn, juliusedimus
• 1974
  • Canto tejido for piano, 7 mn, juliusedimus
  • Melódica (mecano musical) for one or two melodic instruments (for children), between 60 s and 15 mn, juliusedimus
• 1973
  • Canto mnémico four-dimensional fugue for string quartet, 7 mn, Salabert
• 1972
  • Solo para uno verbal score, between 60 s and 15 mn, juliusedimus
• 1971
  • Memorias para teclado for piano or keyboard with 2 or 4 hands, accordion or keyboard percussion, between 4 mn and 14 mn, juliusedimus
• 1970
  • Solo for any solo instrument or for an ensemble of solo instruments, between 4 mn and 8 mn, juliusedimus
• 1969
  • Persona graphic score for trio of non-professional voices: male, female or mixed, 15 mn, juliusedimus
• 1966
  • Tres instantes for cello and keyboard, 3 mn, juliusedimus
• 1960
  • Suite for keyboard, 4 mn about , juliusedimus

Écrits

• Julio ESTRADA & Jorge GIL, Música y teoría de grupos finitos (3 variables booleanas), Universidad Nacional Autónoma de México, Mexique, 1984, 219 p.
• Julio ESTRADA, El sonido en Rulfo : «el ruido ese»[+ CD], Universidad Nacional Autonoma de México, Mexique, 2008.
• Julio ESTRADA, Canto roto, Silvestre Revueltas, Vida y Pensamiento deMexico, Éditions Fondo de Cultura Economica, 2012, 212 p.

Thèses et articles encyclopédiques

• Jorge L. RAMIREZ ALFONSÍN et D. ROMERO, « Embeddability of the combinohedron », Discrete Mathematics, no. 254 (2002), pp. 473-483
• Erik CHRISTENSEN, « Julio Estrada fra kultur til natur », Muskh øst,no.95 (1995), pp. 59–65
• Julio ESTRADA, Théorie de la composition : discontinuum-continuum, thèse doctorat, Université de Strasbourg II, Strasbourg, France, 1994, 500 p.
• Monika FÜRST-HEIDTMANN, « Zwischen alter und neuer Welt » : Julio Estrada im Gespräch über seine Oper Murmullos del páramo », NZM (2006), no. 3, 18 p.
• Monika FÜRST-HEIDTMANN, Estrada, Julio, Grove Music Online, publication imprimée le 20 janvier 2001, publication en ligne : 2001 (mises à jour : 31 janvier 2014, 9 novembre 2009).
• Monika FÜRST-HEIDTMANN, ‘Auf der Suche nach der unverstellten Imagination : der mexikanische Komponist Julio Estrada’, MusikTexte, no. 55 (1994), pp. 39–44
• James L. McHard, *The Future of Modern Music,*Chicago, 2001, pp. 313–330
• Velia NIETO, Recherche-création dans l’œuvre de Julio Estrada, thèse doctorat, Volumes I-II, Université de Paris VIII, Paris, 1999, 511 p.
• Velia NIETO, « El arte de frontera en la música de Julio Estrada », dans Anales del Instituto de Investigaciones Estéticas, automne, année/vol. XXIV, numéro 081, Universidad Nacional Autónoma de México, Mexico, 2002, pp. 123-138
• Carlos SANDOVAL, « Entrevista a Julio Estrada », Heterofonía, numéro 108 (1993), pp. 60-69

Discographie

• Julio ESTRADA, Memorias para teclado, Velia Nieto : piano., Voz viva No. 10, UNAM (México), 1975.
• Julio ESTRADA, Canto oculto, Irvine Arditti, 1 CD Disques Montaigne (The Arditti String Quartet Edition),1990, WM 334 789003.
• Julio ESTRADA, ishini’ioni ; miqi’nahual ; yuunohui’se ; Canto mnémico ; yuunohui’yei’nahui ; Canto alterno ; yuunohui’se’ome’yei’nahui, Quatuor Arditti, dans « Julio Estrada - Chamber Music for Strings », 1 CD Auvidis Montaigne, 1995, MO 782056.
• Julio ESTRADA, eua’on ; eua’on’ome, SWF-Sinfonieorchester Baden-Baden, Olaf Henzold : direction, 2 CD Mode, 2001.
• Julio ESTRADA, eua’on’ome, SWF-Sinfonieorchester Baden-Baden, Olaf Henzold : direction, dans « Donaueschinger Musiktage 1995 », 3 CD col legno, 1996, WWE 31898.
• Julio ESTRADA, yuunohui’tlapoa’se, Irvine Arditti : violon, Jane Chapman : clavecin, dans « Wittener Tage für neue Kammermusik 1999 », 1 CD WDR-Mitschnitt, 1999.
• Julio ESTRADA, Canto mnémico, Kairos Quartett, dans « Interpretenportrait », 1 CD zeitklang, 2001.
• Julio ESTRADA, Hum, Neue Vokalsolisten, Experimentalstudio des SWR, dans « Donaueschinger Musiktage 2002 », 3 CD col legno, 2003, WWE 20229.
• Julio ESTRADA, *Quotidianus,*Julio Estrada : voix, Quatuor Arditti, dans « Donaueschinger Musiktage 2006, Vol. 1 », 1 CD SWR-Mitschnitt / Neos, 2007, 10724.
• Julio ESTRADA, Doloritas. I. Teil der Oper Murmullos del páramo, dans « El sonido en Rulfo:“el sonido ese“ »,**Instituto de Investigaciones Estéticas (UNAM), México, 2008.

Media

• Julio ESTRADA, MuSIIC-Win, Theory d1, Mexico, 2006 [CD-ROM]

Liens internet

• Murmullos de Julio Estrada (vidéo), réalisateur. A. Semichon, TVUNAM (Mexico, 2012) : https://www.youtube.com/watch?v=5sWYBTUh5eE
• Site personnel de recherche de Julio Estrada : http://unam.academia.edu/julioestrada
• « Murmullos del páramo » de Julio Estrada (vidéo),réalisation électronique : Gregorio García Karman, Spiral Hall, Tokyo, Japon, 1 décembre 2010 : http://info.ggkarman.de/node/100

(liens vérifiés en septembre 2020).