Most album covers try to show you something. Aja makes its impression by withholding almost everything. Against a field of deep black, a narrow curve of white fabric and red detail cuts across the image. A face appears only in part. The title, small and red, sits above the name Steely Dan. At first glance the sleeve is almost abstract; a moment later, it becomes unmistakably human.

The woman in the photograph is Japanese model Sayoko Yamaguchi, photographed by Hideki Fujii. Her presence gives the sleeve its mystery, but the image never turns into a conventional portrait. We do not see the whole face or a carefully staged expression. The photograph is cropped so that the boundary between clothing, skin and shadow becomes more important than the information a portrait usually supplies.

Patricia Mitsui and Geoff Westen are credited with the design, with art direction attributed to OZ Studios. Those credits are essential to the story. Fujii made the photograph, but the cover's impact also depends on its selection, placement, cropping and lettering. The small title leaves the picture room to breathe. A less restrained layout might have made the image merely glamorous; here the surrounding darkness makes it enigmatic.

Even the physical finish mattered. A Library of Congress essay on the album records that Walter Becker and Donald Fagen obtained approval for an expensive finish described as “liquid lamb,” giving the original cover additional depth and gloss. That production choice is easy to miss when the artwork is viewed on a phone. On a record sleeve, the dark surface and the reflective finish become part of the experience.

The title itself adds another layer of distance. Donald Fagen has explained that the name came from a Korean woman associated with the family of a high-school friend. It was a name the musicians liked, rather than an attempt to describe the model on the cover. The photograph and the title arrived by different routes, yet the combination feels so deliberate that listeners can easily assume a story linking them. That assumption is part of the sleeve's peculiar magic.

Released in September 1977, Aja arrived when Steely Dan had become less a conventional touring band than a studio project built around Becker and Fagen's exacting songwriting. They worked with an extraordinary group of session musicians, seeking particular performances and textures for individual songs. The music can sound effortless, but its ease is the product of obsessive decisions.

The cover behaves in much the same way. Its apparent simplicity conceals an unusually precise set of choices: a striking photograph, a severe crop, minimal typography, large areas of black and an expensive finish. There is nothing on the front to explain the music's jazz harmonies, shifting rhythms or elliptical stories. Instead, the image offers the same mixture of polish and ambiguity that makes the record compelling.

The songs themselves rarely give everything away. Black Cow opens with the sleek confidence of a sophisticated studio production. The title track stretches into a more expansive form, with Wayne Shorter's saxophone and Steve Gadd's drumming among its most celebrated performances. Deacon Blues turns aspiration and failure into a story that sounds at once seductive and bruised. Peg and Josie bring sharper pop edges. The cover's elegance makes sense beside these songs, but its hidden face also suits their emotional evasiveness.

That is not to suggest that Fujii's photograph was created to illustrate the lyrics. The image had its own artistic life before the album, and its meanings cannot be reduced to a Steely Dan concept. The remarkable achievement of the sleeve is the way an existing photograph and a carefully controlled design became inseparable from the record's identity.

Aja went on to become one of the band's most acclaimed and commercially successful albums, and its cover became one of the most recognizable exercises in restraint in popular music. It remains memorable not because it tells us everything about the people behind the record, but because it leaves so much unsaid.