Björk must have one of the least predictable success stories in popular music. Following Icelandic child stardom and a tenure as the remarkably gifted singer of the fast-to-fade Sugarcubes, she came into her own following the release of 1993’s Debut, an often sublime mixture of techno and pop held together by Björk’s instantly recognizable, though elusive, persona. As each subsequent effort (the ebullient Post, the dense but rewarding Homogenic) pushed her music further toward the vanguard, and each new release became a hotly anticipated event, Björk’s voice kept her efforts grounded in the realm of human emotion.

The push and pull between human and machine on her past efforts fades on Vespertine, her best album to date. The keynote to Björk’s songs is joy, a quality that made her casting as the fatally optimistic heroine of Dancer In The Dark all the more inspired. Even her sad songs seem like elegies for past happiness. The new, largely self-produced Vespertine presumably takes its title from vespers, the time for evening worship in the Catholic church, and a sense of hushed twilight reverence, sometimes spilling over into ecstasy, pervades the album.

The objects of worship shift from song to song—a boy on “Cocoon,” the Northern Lights on “Aurora,” something sensual and mysterious on “Pagan Poetry”—but the hushed tone remains the same. It might sound that way even if several tracks didn’t feature the singer accompanying herself as an overdubbed choir, or if harps and celestes didn’t play roles as important as programmed beats. Vespertine is an album of small gestures, one almost challenging in its stillness.

The beats don’t so much push the songs along as get dragged behind them, occasionally even dropping out entirely. Halfway through, one stretch of songs bases itself on the haunted sound of arranged music boxes, while at other moments, Björk’s voice wraps around the strings as if the two sounds came from one source.

The cumulative effect is an album both timeless and of the moment, an avant-garde electronic-pop exploration of classic themes. By this point, it’s become almost a cliché to describe Björk’s music as ethereal, but Vespertine suggests even loftier terms. It sounds closer to heaven than the ether below.