Pop music doesn't get any more sophisticated or intelligent than Steely Dan. And of the band's seven albums, none is more impressive than the groundbreaking "Aja." Brimming with rich melodies in challenging arrangements, it fuses pop and jazz in a way that is both complex and accessible. The exotic title track may be the boldest composition in the formidable Dan canon: Built around an inspired instrumental section featuring Wayne Shorter on saxophone, it dazzles with robust rhythms and mesmerizing textures. Steely Dan sometimes was criticized for its deliberate, painstaking ways in the studio, close attention to detail that is particu larly evident on this meticulously crafted album. Yet the ultra-clean production values--and the use of some of the '70s' most gifted studio musicians--bring an appropriately cool elegance to these upscale songs. "Aja" also contains some of Donald Fagen's most inviting vocals: He contributes a late-night allure to the suave "Home at Last" and an infectious enthusiasm to the effervescent "Peg." The most timeless track, "Deacon Blues," is a lovely song delivered with sublime grace and bittersweet emotion; it's one of the great ballads of the rock era. "Aja" simply is an indispensable album by an indispensable group.