September 9, 2022

An Interview with Manfred Mohr

The legendary computer artist speaks to Aleksandra Jovanić about algorithms, music, and the logic of generative art
Credit: Manfred Mohr, P3010_3 (detail), 2020-2021. Courtesy of bitforms gallery
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An Interview with Manfred Mohr

At RCS we believe that, wherever possible, artists should be the ones to shape the terms by which their work is critically evaluated. This is especially appropriate when it comes to generative art, which is finally receiving the mainstream attention it always deserved. With one of its pioneers, Manfred Mohr, currently exhibiting at bitforms gallery, RCS asked one of the leading lights of the new generation, Aleksandra Jovanić, if she might lead a conversation about the logic of generative art.

Manfred Mohr: I didn’t wake up one morning and suddenly use code and a computer — it was a very long thinking process in my life. I come from the abstract world of music. Music is always the basis of all my thinking. My early interest in visual art was therefore strongly influenced by jazz and classical modern music, reflecting a kind of action painting. The problem was, I could not really control my artwork. In music, I could write down tunes, etc., but with action painting I had no real control.

It was only when I got into the philosophy of Max Bense in the early 1960s that I understood that “rational” thinking in art, as Bense proposed, could solve that problem. One has to create the logic of what one wants to do before one starts.  

My artistic work therefore started and continues today by dissecting and finding the inner logic of what I want to do. I create out of an abstract logic something which becomes visual.
Manfred Mohr, P-016-7089, 1969. Courtesy of bitforms gallery

Aleksandra Jovanić: We all make an algorithm whenever we make our generative pieces. At the beginning of last year, I was part of a team that was developing an interdisciplinary course for high school students. The aim was to connect art, mathematics, and programming. I dedicated one of the chapters to your Random Walk, which is one of my favorite algorithms because when I don’t know how to continue with one piece, then I try to take the next step in a random way. Do you have a favorite algorithm or set of algorithms?

MM: If you have four sons, you cannot say you have a favorite one. All algorithms are equal in their logical sense. But, I must say, Random Walk from 1969 was one of the first algorithms I wrote which worked and therefore has a special historic value to me. Like all digital artworks, I see it as a three-fold interdependent process. Ice, water, and steam are all the same, but represent different states. I see the code/logic as one state; the running of the program and getting a data file (result) as a second state; and the visual result as the third state. None of them can exist without the other. 

I think digital art is something which, in a sense, does not really exist until it becomes a physical reality. And that reality is a new reality, which Max Bense called “rational art.” 
Manfred Mohr, P-014-1415, 1969. Courtesy of bitforms gallery

AJ: Do you start with the code?

MM: Sometimes I have an exact idea and sometimes I have only a vague idea of what I want to do. Sometimes, I make some sketches; it depends on what it is. I start by writing the code and at the same time figure out how everything builds up logically. I remember very well when I met Pierre Barbaud, the French composer, in 1967, who was one of the first composers to write music with a computer. He explained to me how he composed his music: putting bits of sound, which he called “êtres musicaux,” together and then calling these in a program through subroutines which generated an output based on statistical decisions.

When you do something, you always have to build on something. You cannot invent something out of the blue. So my early pieces, like Random Walk, are based on my musical past. Most of my first drawings, for the first two or three years, were more or less linear, as one would write music. It was very easy for me to invent ten independent algorithms a day. However, this made me think that I should work on more complex systems where all my ideas are interrelated and help in developing each other.

I went back to thinking about music and musical instruments and thought: “why couldn’t I invent a graphical instrument that generates graphics?” I came to the idea of the cube and decided that it could be my instrument. I started working with the cube by taking it apart, line by line, looking at different graphical aspects. Out of this, I developed a whole graphical alphabet which replaced the linearity of my earlier algorithms.

Manfred Mohr, Cubic Limit, 1973-74. Courtesy of Carroll / Fletcher

I lived in Paris in the 1960s and ’70s, and there was a mathematician, René Thom, who worked on something which he called the “catastrophe point.” For example, if you have a book on a table and you push it to the edge of the table, that last millisecond as the book starts to fall to the floor is called a catastrophe point. I thought: “If I make a movie where I remove lines from the cube, there must be a catastrophe point where I don’t see the cube anymore.” Of course, it didn’t happen. I made the movie and there was no catastrophe point.

The problem is that our brain is too conditioned; we know what three-dimensionality is. Even if you see one line rotating in space, you feel the three-dimensionality. That movie, Cubic Limit (1973-74), became the source of my development of graphic signs — signs which refer to themselves. I immediately realized that I wasn’t interested in showing the whole cube or hypercube. I was only interested in the system and that I can do something with it by selecting aspects of the structure. The English language (and French and German) have 26 letters, but we never show them all together as a system. We choose letters and construct words. In music we do the same, we choose single notes from the system of 12 halftones in an octave and create a sound cluster.

In my work, I do exactly the same thing. I choose from the structure, cube or hypercube, aspects which are sometimes in themselves very complex and let the computer draw these lines. It’s only then that I can see how my ideas appear. For example, I calculate a diagonal path through a hypercube which is a very interesting line because it goes through each dimension once.

Nobody can imagine a multidimensional structure, but we can calculate it and get incredible visual results from it.
Manfred Mohr, P3010_2, 2020-2021. Courtesy of bitforms gallery

AJ: I had a bunch of exams, where we dealt with n-dimensional matrices. And it was really hard to imagine n-dimensional space where things happen, but you project parts of it onto a two-dimensional screen. And it’s really fascinating to me, the system you’ve developed for your pieces. How important is it for you that viewers understand the algorithm — your system from which you develop images?

MM: If someone looks at an abstract painting, they don’t ask: “what is that?” With my work you could ask: “what is it?” And I can explain the program to you.

I think that digital art, at least how I program, has more to do with logical content than any other art. Normally, art has a social content. My work has a logical content which also relates to the world in multiple ways.
Manfred Mohr, P3010_5, 2020-2021. Courtesy of bitforms gallery

AJ: It’s inspiring for me to see the mathematical methods you’re using, how you describe the algorithm, and then to try to imagine it [myself]. It’s a different kind of inspiration, not a visual type of inspiration, but something like logical inspiration.

MM: My art is a nightmare for mathematicians because I don’t prove anything. I use mathematics to create my work but it’s not the mathematics which I want to show. What I want to show is the visual invention which is generated from it. If somebody who has no idea about music listens to Mozart’s Horn Concertos, the question is: “Who is more open to the music? The musician, who knows it’s the most difficult piece to play, or the one who doesn’t know anything?” With visuals, it’s similar. If you’re open to enjoying the visuals, you get it. If you watch, for example, my moving images on the screen, you may not understand the logic, but you can see that something holds everything together. 

I’m not reflecting or proposing any social solutions in my art, but it is connected to our time through my artistic sensibility. I’m not interpreting the world, I am creating a world.  

When I started writing code in 1969, the question was: “How can I judge this? Is this good or bad? When is it finished?” Eventually, I get to a point where the program does absolutely what I want. And then I say: “Okay, that’s it, the program is finished. Whatever it does now, I have to accept.” Sometimes I do not like an individual output but I have to live with the visuals. If you listen to J.S. Bach, for example, there are situations where the harmonics sound strange, but they are not incorrect. It is the result of the logic. If I make, for example, ten plotter drawings, I might not like two of them but they’re a part of it and I accept them.

Manfred Mohr, P3010_3, 2020-2021. Courtesy of bitforms gallery

AJ: Since I’ve been doing interactive pieces or pieces that are generated when the viewer starts the code, I have always been curating the outputs and have always liked the outputs, even those that were not framed well. Somehow the code, or the algorithm, decided to make some kind of composition that I would never have thought of, and I get excited about those results. I think [the concept of] “long-form” generative art was probably influenced by the market. When people are buying NFTs, they want a variety of outputs in order to appreciate one collection or one code. But most of the time, when we make the code, we make some limits. And inside of those limits, we know what the output will be.

MM: I think that if you write an algorithm, and the algorithm is accepted by you, that’s what it is. For example, John Cage wrote a piece, Radio Music (1956), where, if I remember correctly, nine radios are involved and the rules are written down — when to turn on and off the radios and which frequencies to turn to. If the rules are good, the output has to be good.

AJ: Your plotter drawings are very famous. Could you perhaps reflect on the differences between the physical and the digital in your work?

MM: The physical output is very important to me. In the past, plotting was a very painful thing [because], if somebody turned off the lights in the room next door, the plotter sometimes stopped. But nowadays, with inkjet printers, it’s much easier. I like to have something which I can put in my drawer. Maybe this is my upbringing, or my age, [but] I prefer to be able to hold something in my hand than to have it running somewhere virtually, even though I [also] like things running on the screen.

Manfred Mohr, Print-23, 2022-21. Courtesy of bitforms gallery

AJ: Also, most of the time, a screen is not the ideal medium for this type of digitally generated static image. But if it’s an animation or something interactive, then it makes sense. For my generation, plotting is maybe something we discovered recently, something in fashion. I also like to have something rendered in real space. But I don’t always have to plot it; sometimes I do digital prints. I also do 3D prints. So the topic comes first, and then I find the best [way of] rendering that piece.

MM: I agree that the physical world needs physical objects. But when I made my first drawings in 1969, I went to my gallery in Paris to show them what the machine had drawn, and they threw me right out of the gallery, saying: “That’s not art.” It’s very hard for art lovers to accept that a machine can draw something where the emotions are not directly visible, but I can assure you that emotions are omnipresent while writing the program. It reflects one’s thinking and the program renders one’s thoughts into a logic.

At my 1971 solo show at the ARC-Musée d’Art Moderne de la Ville de Paris many people were negative about computer art. As a result, I did not mention the computer at my 1974 show in Paris at Galerie Pierre Weiller even though I was showing pen plotter drawings.

At the opening, a man came and tapped me on the shoulder and said, “You know, looking at your drawings, you should go into computers.” I was so happy because that was exactly what I wanted to hear, that somebody understood what I was doing.
Manfred Mohr, Print-20, 2022-21. Courtesy of bitforms gallery

AJ: What can you tell us about your new show at bitforms gallery?

MM: The show at bitforms comprises my latest works from 2020 to 2022. In the past, I’ve often used different algorithms to break the symmetry of cubes and hypercubes. Breaking the symmetry opens up a new world of relationships.

In my new show, “liquid symmetry,” I’m using symmetry in a new way. This phase of work is based on a diagonal path through an 11-dimensional hypercube projected in two dimensions — shown as a thick white line connected to its symmetrical counterpart along the edges of the hypercube, seen as a thin gray line. These two paths are connected at their common end points. A red symmetry line is drawn through these end points and extended to the limiting square of the work space. Each line segment of the white line is associated with a randomly chosen color, whereas all segments of the gray line are associated with one solid gray color. A second but darker solid gray color fills the original space between the two diagonal paths. In tiny angular steps, the two linked diagonal paths (white and gray lines) are rotated in 11D for 20 seconds and projected in 2D, leaving color traces (color fields). This procedure breaks down the symmetry of the moving object visually. This phase of my work also includes aluminium reliefs and wall structures that are bent along the red symmetry line. The algorithm generates the shape and content of all the works. 

In 1962, I decided to work in binary, I wanted to say everything in ones and zeros. Thus, for 30 years, I only worked in black and white. In 1978, I started to use higher dimensions in my calculations, and by 1999 it had become practically impossible for me to communicate to people what I was doing. Even though my work looked minimal, the content was very complex, indeed maximal. I thought: “If I link the spatial rotation to color, maybe people will relate more easily to it, because they will see a structure which holds everything together.” I started writing animations which used random colors (distinctions) to indicate spatial relationships.

Thus, I changed my mind after 40 years, reversed my philosophy of black and white, and succeeded in communicating the complexity of my algorithms.
Manfred Mohr, Print-24, 2022-21. Courtesy of bitforms gallery

AJ: Artists are always exploring new technologies — getting to know the technology, then the limits of the technology, and then freely creating with the technology.

MM: In the 1960s and ’70s, there was no digital art — the word was not even invented yet — and graphic screens based on dot matrices were just beginning to appear. The only way you could visualize a result was through linear vector drawings. In the 1980s, when the first home computer emerged, the matrix screen became a new dimension. One could access single dots on the screen and manipulate the image, and soon after color screens were invented. But as a ground rule: whatever anyone can imagine — even the most impossible thing — if a human being thinks of it, at a certain point in time it will become reality.

AJ: If you can tell it to someone, then you’re on a good way to express it as an algorithm. Then you can make it.

MM: Einstein said: “If you cannot explain to someone in simple words what you are doing, you do not understand yourself what you are doing.”


Manfred Mohr’s solo exhibition “liquid symmetry” runs from 9 September until 15 October, 2022 at bitforms gallery, New York.

Manfred Mohr is a leader in the field of software-based art. In the early 1960s, he discovered Max Bense’s writing on information aesthetics. These texts radically changed Mohr’s artistic thinking, and within a few years, his art transformed from abstract expressionism to computer-generated algorithmic geometry. Encouraged by the composer Pierre Barbaud, whom he met in 1967, Mohr programmed his first computer drawings in 1969 after learning the Fortran IV programming language to create compositions that he executed as ink drawings on paper. He started his research in 1969 at the Faculty of Vincennes, Paris in the group “Art et Informatique,” where he co-founded the seminar. 

Some of Mohr’s earliest drawings were executed on a light pen plotter (1969) and also on a large Zuse flatbed plotter at the University of Darmstadt in Germany (1970). However, in 1970, he contacted the Institute of Meteorology in Paris, which granted him access to a Benson 1284 flatbed plotter and a CDC 6400 computer, the most powerful machines available at that time. Mohr’s first major museum exhibition, “Une esthétique programmée,” took place in 1971 at the Musée d’Art Moderne de la Ville de Paris. It has since become known as the first solo show in a museum of works entirely calculated and drawn by a digital computer. Mohr’s pieces have been based on the logical structure of cubes and hypercubes — including the lines, planes, and relationships among them — since 1973.

Mohr’s work is in the collections of the Centre Pompidou, Paris; ZKM, Karlsruhe; Whitney Museum of American Art, New York; Joseph Albers Museum, Bottrop; Mary and Leigh Block Museum of Art, Chicago; Victoria and Albert Museum, London; and many others worldwide. Mohr is the recipient of an ACM SIGGRAPH Distinguished Artist Award for Lifetime Achievement in Digital Art; Golden Nica from Ars Electronica, Linz, Austria; the Camille Graesser-Preis, Zurich; D.velop Digital Art Award, Berlin, and a New York Foundation for the Arts Fellowship.

Aleksandra Jovanić is an artist and programmer from Belgrade, Serbia, who holds a PhD in digital arts and a BSc in computer science. In her research and artistic practice she combines various media, mainly focusing on interactive art, art games, and generative art. As an assistant professor, she teaches at the new media department at the Faculty of Fine Arts in Belgrade.