Just when everyone thought Bjork had become as radical as can be, the Icelandic phenom up and decided to do away with instruments. August 31 marked the release of her latest album, Medulla: fifteen tracks in which the techno diva goes a capella.

According to www.bjork.com, the singer had not originally planned for her album to be devoid of instruments. Once the recording was finished, Bjork was unhappy with the results and found that dropping out the instrumental parts gave the work more clarity.

Aside from the complete departure from instrumental music, Medulla still sounds like Bjork. The electronic mixing of her earlier albums is replaced by voices that are electronically manipulated. Collaborating with Inuit throat-singer Tanya Tagaq, Japanese a capella artist Dokaka and Rahzel of the Roots, among others, Bjork’s album celebrates the human voice as the most fundamental of instruments.

Continuing to pursue experimental, atonal music, some of the sounds on Medulla are anything but pleasant. Track one, “Pleasure Is All Mine,” and track eleven, “Ancestors,” both incorporate sounds that would not be considered musical in the traditional sense. Vocal percussion is interspersed with heavy breathing, talking, chanting, whistling, growling and an animal-like panting. Listening to Medulla with the volume turned up high could be a scary experience — like being lost in the jungle at night.

On other tracks, Bjork soars above a wonderfully harmonic accompaniment of what sounds like male and female choirs. Track six, “Who Is It?”, and track eight, “Desired Constellation” prove that Bjork has a powerful, evocative voice. It is easy to follow the emotions she expresses in each song thanks to her clear, dynamic instrument that travels smoothly through the swells and ebbs of her compositions.

In some songs, like track two, “Where Is The Line With You?”, the choir harmonies make the music seem almost churchy (an term that would make Bjork cringe), yet within those same songs she aggressively changes from one extreme to the another. Angelic sopranos parts are juxtaposed with dark, bass sounds from the drums or “beatbox.”

One thing Bjork seems to have mastered in Medulla, her seventh album, is the art of variety. From her first solo album, humbly titled Debut (1993), to Vespertine (2001), Bjork’s music gradually shifted from upbeat techno into slow, emotional reflections on life and love. The artist excelled in both styles, but in her later albums like Homogenic (1997), Bjork wasn’t able to intersperse slow paces with fast ones, making it hard for the listener to tell one song from another. Medulla, however, is a mixture of fast and slow beats that keeps the listener interested all the way through.

Despite her dedication to going where no music has gone before, Bjork has had sellout moments along the way. Occasionally, she writes a lyric that rhymes, lending a symmetry to her work that makes it suddenly sound more mainstream. One example of these sellout songs is “It’s Oh So Quiet” from the 1995 album Post. The rhymed lyrics (“It’s oh so quiet, it’s oh so still... you’re all alone, and so peaceful until... You fall in love”) coupled with big band instruments had Mariah Carey fans everywhere suddenly declaring themselves Bjork fans as well. It was a catchy cliché, paired with a catchy tune. Basically, it sounded as if the hit number from a Broadway musical had somehow landed in the middle of Bjork’s techno-punk album.

Medulla, like Post, throws in its own surprising sellout. The sixth track, “Who Is It?” is another one of Bjork’s rare compositions with rhyming lyrics: “Who is it that will never let you down? Who is it that will give you back your crown?” Again, the melody is clever and the rhymed chorus is painfully predictable. Like “It’s Oh So Quiet,” “Who Is It?” sounds non-radical, and therefore, non-Bjork. The song will no doubt draw the same following of pseudo-Bjork fans as “It’s Oh So Quiet.”

Even with her rare sellouts, no one can deny that Bjork is a prolific and versatile artist whose music is always full of mysterious twists and turns. She is constantly experimenting — thinking up new ways to sound and new ways to be a contemporary musician. Medulla is sure to leave every listener wondering, “What will she come up with next?”