As someone who teaches visual art to musicians and dancers, I have long been fascinated by synesthesia, a term describing the involuntary joining of the senses. Most of us assume that everyone sees and hears things the same way we do, but synesthesia provides proof that this is not necessarily the case. Scientists have found it difficult to study synesthesia because of its idiosyncratic nature; there is no uniformity in the way individual synesthetes experience colored sounds, colored letters, or textures of music. However, the artwork and recorded statements of numerous synesthetic artists clearly show the existence of recurrent patterns. This discovery helps us to better understand the entire synesthetic phenomenon, and perception in general.

The form of synesthesia most familiar to those in the arts is “colored hearing,” the coming together of color and musical sound. Thanks to current and ongoing research, we now know that this is only one of more than 54 forms that synesthesia (regarded at different times in history as something odd, or highly desirable) can take. We still do not know how many synesthetes there are. Just a few years ago, it was thought that perhaps one person in 25,000 had synesthesia; today, scientists believe it is far more common, affecting as many as one person in 100.

In recent years, an increasing interest in synesthesia has resulted in quite a number of exhibitions featuring “visual music.” But most of them have dealt only with metaphorical (voluntary) rather than genuine (involuntary) synesthesia. Several shows have also featured sound-art, in which artists have attempted to replicate synesthesia by means of computers.

An exhibition at McMaster Museum of Art in Hamilton, Ontario (Canada), that runs from September 18 through November 15 will be different. Indeed, it is the first to place genuinely synesthetic artists in context, and examine shared characteristics in their art. Presented in conjunction with the university’s neuroscience department, it also examines assumptions about art and the brain. Do synesthetic artists share common shapes, colors, or ways of seeing? Are they consciously using their visions to create their work? Are they aware that they might be using these abilities creatively? How do non-synesthetes perceive images in the work of synesthetic artists? And perhaps most challenging of all, which artists are synesthetic?

In addition to the art of four known synesthetes—David Hockney, Joan Mitchell, Marcia Smilack, and Carol Steen—we are including works by Charles Burchfield, Tom Thomson, Kandinsky, and Van Gogh. Burchfield has clearly suggested, in numerous journal entries, that he might have been synesthetic. Thomson, well known in Canada but not in the United States, is a new discovery for us. We perceive elements in his work that match some in Burchfield and other synesthetes. And Van Gogh and Kandinsky also qualify as might-have-beens.

Hearing a recent performance of synesthetic composer Olivier Messiaen’s Des Canyons aux Étoiles helped me to identify some commonalities that apply to visual art as well as musical composition. In this work, the composer illustrates musically his enchantment with the sights and sounds of Utah’s Bryce Canyon. Especially intrigued by birdsong, he also describes the wind and the colors of the landscape. It is no coincidence that all the visual artists in our show also respond ecstatically in their art to the colors, sounds, depths, and complexity of nature.

In order to convey the canyon’s impact, Messiaen makes use of anomalous musical techniques, including instruments played in a highly unconventional manner. For example, the French horn uses flutter-tonguing, arpeggios, and pitch blending; the trumpet wails, making shrill sounds; percussion and special machines evoke wind; the piano uses the entire range of the keyboard to produce overtones that sing out after the notes have been played.

Likewise, synesthetic visual artists often use unusual techniques and perspectives. Steen expresses her artistic vision by applying oil paint with her fingers; Smilack photographs reflections upside down when she “hears them,” and Hockney creates opera sets according to the sound that informs his colors. Kandinsky claimed to have discovered abstraction upon seeing one of his works wrong side up. Synesthetes invariably manifest a multilayered, complex way of looking at and interpreting things. In synesthetic art, both paintings and music exploit unexpected and startling rhythms.

I thought it might be interesting to explain firsthand how a museum exhibition like this one comes together. The planning began a year in advance. In August 2007, the director and curator of the McMaster Museum of Art asked Steen and me to help conceive and carry out an exhibition in conjunction with McMaster’s department of psychology, neuroscience, and behavior. While the museum was booked several years in advance (as are most cultural institutions), they were able to free up a gallery that was to have held an exhibition from their permanent collection. We began telephone conferences and planning the exhibition in September, and conversations and site visits have been ongoing all year.

The theme of the exhibition is the role of synesthesia in the creation of art, and an examination of common characteristics in artists we know to be synesthetic (as well as a number who might be). After coming up with the general concept, we had to compile a list of artists, then select specific works that would best illustrate our ideas. We had to locate the art we wanted, and then obtain the agreement of lenders. Co-curator Steen and I made numerous visits to galleries, artists’ studios, and museums, and we searched for pieces online as well. The job of assembling the works for the exhibit posed a number of problems in locating and acquiring the art, as well as obtaining permissions and agreements. The financial aspect, of course, was also a major consideration. It can be very expensive to borrow, restore, conserve, frame, pack, and transport these pieces safely.

After we had chosen the works and the museum had obtained the loan and copyright agreements, Carol and I visited the university in order to see the gallery, so that we could envision exactly how the art would be displayed.

Next, there was the question of a catalog to document the exhibition. We needed writers and designers to put the information and illustrations together. The museum director was extremely supportive, selecting a rather expensive format, for which we asked six scholars to write essays. When the artworks arrive at the gallery on September 9, we will install them over the next two days, conduct a workshop, arrange for the opening, and help coordinate the publicity.

A show that we hope will look effortless demands hard work. We expect that the exhibition will bring about a new and intense kind of visual thinking. In addition to exploring aesthetic beauty, its aim is to challenge assumptions, as it is supported by actual observation and new information. Although the show takes place in Hamilton, Ontario, and I do not anticipate that many of you will be able to see it in person, there will be an extensive catalog available. The catalog will ensure that the scholarship will be accessible to many who can’t attend, as well as providing a lasting record of the research involved.