In writing a short essay using the "animation" prompt, the possibilities were virtually endless. I could have chosen a film by Norman McLaren, Oskar Fischinger or Len Lye. I could have picked a film by Lotte Reiniger or Walter Ruttmann. I could have picked any number of the animated feature films or television series that have been released in the past decade. But I chose a film by Mary Ellen Bute, partly because of Bute's interest in exploring the formal possibilities of this art form, partly because she was a pioneering female animator, but primarily, at the heart of it, because of how much I enjoy this particular film. Animation, at its most basic level, is about movement, and Spook Sport (1940), like many of Bute's films, is an experiment in movement or, more specifically, about exploring the connections between music, movement and light.

Spook Sport opens with the following intertitles:

"In the following short film novelty – colour, music, movement COMBINE to present a new type of Film-Ballet"

The titles are, as is suitable for a film-ballet set in a graveyard, animated in glowing red, green and yellow, to match the cast of "characters." Spook Sport is an experimental animated short film in which "spooks" and ghosts dance around the graveyard at midnight. The red spooks and green ghosts (little more than abstracted shapes and lines, although recognisably "figures"), along with some bats and bells, flit and swoop across the screen in mesmerising fashion, set to Camille Saint-Saëns' "Danse Macabre." It's delightfully spooky.

A decade earlier, a very different film had been made about a dance in a graveyard – the Walt Disney Silly Symphony, The Skeleton Dance (1929). In this animated short, drawn by Ub Iwerks and with original music by Carl Stalling, skeletons rise from their graves to perform a highly synchronised dance. It was a triumph of the time when cartoons set to pre-recorded music were still in their early days. Described by Disney and Stalling as a "musical novelty," The Skeleton Dance was to be the first in a series of cartoons set to music.1 But whilst The Skeleton Dance is recognisably Disney in the elasticity of its characters and its approach to a kind of "realism" (the cats and skeletons in the film are clearly cats and skeletons), Mary Ellen Bute's Spook Sport is an experiment in abstraction – it is a play of light, sound, movement and colour.

Made in collaboration with Norman McLaren (another animator who pioneered experimentation with music and colour in film), Bute's film actively resists any sort of hyperrealist aesthetic or representational filmmaking that most commercial animation studios were becoming known for at the time. In Spook Sport, the figures were drawn directly on the film strip. One of the earliest independent female animators in the United States, Bute was interested in the ways cinema could be used to explore music, rhythm and colour. According to Kate Saccone, Bute "saw the art of film in more scientific ways, relying on mathematics and numerical composition or technology like the oscilloscope to create her films."2 This precise approach to filmmaking makes the balletic qualities of Spook Sport at once all the more remarkable, and understandable – ballet, of course, is as much about precision as it is beauty and grace.

Spook Sport is perhaps one of Bute's most famous works and, for me, one of her most playful. The spooks and ghosts are at times graceful, and at other times frenetic and wild, as in the moment shown in the GIF that accompanies this essay. At all times, though, they are perfectly matched with the music. It is an enthralling combination of light, form, movement, and sound which, uncoincidentally, is the title of Bute's 1935 essay on the concept of The Absolute Film.

"Light*Form*Movement*Sound" has been described as Bute's "manifesto"; in it, she muses on how these four elements interact to create something which approaches what she calls The Absolute Film, "a stimulant by its own inherent powers of sensation, without the encumbrance of literary meaning, photographic imitation, or symbolism."3 For her, creating films were about experimenting with music and colour, and she was mostly unconcerned with story or realism. She was also interested in being able to "paint with living light,"4 turning to film after first studying painting, and then stage lighting. This experimentation with light can be seen in many of her short works, including Escape (1937), Parabola (1937) and Tarantella (1940), to name but a few.

Bute's films are associated with the abstract and the avant-garde and they are an excellent example of the possibilities and diversity of the animated form. For most, the term "animation" calls to mind the commercial features that we commonly see in movie theatres from studios like Pixar, Disney and DreamWorks or, perhaps, beyond western animation, the films of Studio Ghibli, or the critically acclaimed animated series aimed at older audiences.5 Animation as such is often discussed in terms of its content or thematic concerns, rather than its formal attributes. Sparing a moment to consider what animation can mean and be, you begin to see that animation is everywhere – feature films, TV, advertisements, online, games – even many examples of what we would traditionally consider"‘live-action" cinema or television contain CGI or "invisible animation" that we aren't meant to notice. The terms ‘abstract animation' and ‘experimental film' are often used interchangeably, further complicating definitions.6 As Suzanne Buchan, a scholar of animation aesthetics, so aptly explains, "Animation is pervasive in contemporary moving image culture."7 Anyone who has attended an animated shorts program at a film festival, or indeed any kind of animation festival, will be aware of the diversity of animation the world has to offer.8 Direct-on-film animation, sand-animation, puppetry, digital, various forms of stop-motion and "traditional" 2D drawn animation are but some examples.

The films of Mary Ellen Bute (and those who came before and after her) pushed the boundaries of experimental animation and cinema in ways both playful and profound. Bute's work exemplified the possibilities inherent in the form itself, the ability to combine time, light, movement, and sound in the most unique ways. Spook Sport is but one example of Bute's experimentation; the figures of light, dancing in synchronisation to the music, is representative of what Bute was trying to achieve with her filmmaking, and does so in a way that remains both beguiling and innovative. Her work continues to inspire.