Fruit loops.

"Architecture is frozen music," Friedrich Schelling remarked at the beginning of the nineteenth century, signaling both the distance between these two arts and their proximity. In some respects, they lie at opposite ends of the aesthetic spectrum: Music is the most ethereal, immaterial, and temporal of arts, architecture the most earthbound and palpable. Yet they have always shared a secret affinity. With rare exception. Western music is played and heard indoors and has always had to respond to the shape and stuff of its constructed environment. It's no accident that the Gregorian chant - with its cavernous expanse and long sustain - is the musical art of the Gothic cathedral, or that chamber music is, well, chamber music: the intricately ordered sound of the Baroque drawing room. There is also a long tradition of Western art music composed for (or inspired by) particular buildings and spaces, from Guillaume Dufay's 1436 motet, Nuper rosarum flores, written to mirror the proportions of a Brunelleschi dome, to Edgard Varese's Poeme electronique for Le Corbusier's 1958 World's Fair pavilion, and Morton Feldman's Rothko Chapel of 1971. The latest and most notable addition to this genre is David Toop's fantastically weird aural complement to Itsuko Hasegawa's Museum of Fruit, a trio of bulbous greenhouses set in the river valley below Mt. Fuji.

Narrowing the gap between music and architecture, twentieth-century music has increasingly traded the temporal terminology of "melodic development" for the spatial and tactile language of "density," "volume," "mass," and "soundscape." The shift is most apparent in ambient music, where sound doesn't so much unfold in time as occupy a space (hence the epithet "wallpaper music"). On the other side, thanks to computer-aided design, architecture has become more buoyant and dynamic, capable of angles, arcs, and asymptotes only imagined until now.

Hip to this new aesthetic confluence, the ambient-electronica label Caipirinha Productions launched its "Architettura" series last year, calling on auteurs of synthetic sound to interface with high-tech structures of their own choosing. In the first volume, Savvas Ysatis and Taylor Deupree take on Toyo Ito's Tower of Winds - not so much a building as a massive electronic sculpture in Yokohama that responds to environmental changes with spectacular displays of light and color. The duo serve up a batch of bleeps and throbs to match the tower's protean changes, but the sound track doesn't stand up on its own. On volume two, Testu Inoue pushes mimesis a step further, feeding digital photographs of Nicholas Grimshaw's Waterloo Terminal through a battery of audio software. The result is the most oddly mediated of things: sounds translating images representing glass and steel. And while Inoue's gorgeously refracted and reticulated pieces capture the terminal's textural details, they do little to reflect the structure's striking totality, an enormous glass larva that snakes up through London's South Bank.

Toop's contribution, volume three in the series, is the clear standout. The author of poetic and erudite books on hip-hop and ambient sound, Toop is also a cosmopolitan and sonically omnivorous musician who has worked with John Zorn, Talvin Singh, Evan Parker, and Prince Far I and has released three marvelously syncretic records of his own. On Museum of Fruit, Toop's strategy is less literal and mechanical than that of his "Architettura" colleagues, but he produces a work that is at once more resonant with its architectural inspiration and more autonomous. He fabricates a parallel sonic environment, disclosing an extraordinarily strange and beautiful garden of cyborg flora and fauna. Each sound is revealed as a unique form of life, and the entire record unfolds like a microscopic documentation of hypernatural events.

Familiar and strange acoustic instruments poke out from a thicket of electronic signals and bustling digitalia. On the opening track, a mournful shamisen wails over a sinister insectile buzz. Further in, "Breathing Chaos" juxtaposes the sounds of proximity and distance: lips and breath on a woody shakuhachi, the subsonic echo of a dubby bass. In "Glass for Paper," a simulated howling menagerie emits feedback roars and deep-sea moans. And "Smell of Human Life" contrasts a thunderous oscillating rumble with irregular knocks and slaps of metallic and shimmering percussion.

If Schelling is right, then music and architecture meet where architecture thaws and music congeals, and Toop and Hasegawa's hybrid marks the point at which the two become one, where music becomes a machinic organism secreting a crustacean shell of glass and steel.

Christoph Cox writes frequently on music.