For more than 30 years, Ladysmith Black Mambazo have shown that "Music Knows No Boundaries." It is therefore no coincidence that their recent release, Raise Your Spirit Higher (Heads Up), includes a song of the same name.

Led by Joseph Shabalala, the group has transcended cultural differences, despite the fact that most of their songs are in a language that few people outside of South Africa can understand. They bridge the social divide in many ways, mainly by fusing the traditional Isicathamiya (Zulu a cappella) with gospel stylings.

Ladysmith first gained international notice after they contributed vocals to Paul Simon's "Homeless" and "Diamonds on the Soles of Her Shoes," both tracks on his seminal 1986 LP Graceland . Since then, they have worked with artists ranging from Ben Harper to Dolly Parton, and have also sung on a Life Savers commercial.

Raise Your Spirit Higher continues the all-male a cappella style featured with Simon on "Homeless," and incorporates strong messages into the music. Ladysmith break through the limitations of the a cappella format by creating a variety of sounds with their mouths. The album serves as both a piece of art and as an outcry of activism, most explicitly featured on "Fak' Ibhande (Don't Drink and Drive)." According to the album jacket, the song, which at times resembles a vocal round, also addresses the issue of using seat belts.

After first listening to Raise Your Spirit Higher, it becomes clear that without the use of instruments, Ladysmith are still able to create complex music. Their unique blend of ten voices allows for complete coverage of all vocal registers. To this they add vocal percussion, featured on "Uqinisil' Ubada (Lord Is The Light and Truth)." By collectively making a clicking sound with their mouths, the group is able to replace the sounds of actual percussion instruments.

When tongue rolls and other clicking noises are added to this, one begins to have a higher understanding of the music's purpose. Throughout the album, Ladysmith are largely able to capture the diverse sounds that can be created with the mouth. As the band believes, their act of musical creation in this context represents giving a gift back to God.

Ladysmith's sound clearly illustrates that song lyrics do not necessarily need to be understood for music to be effective. Even during the first listen to "Wenyukela (Raise Your Spirit Higher)," one begins to sing along with the choruses and verses. The song illustrates the effect of the group's continual, driving hymns, as Ladysmith's collective voices create a soothing musical atmosphere.

On "Black is Beautiful," Ladysmith continue to represent a message of unity, while at the same time displaying a sense of national pride. The group, in an intriguing rhythmical manner, repeat that "I am so glad...to have many friends, black and white, Indians and colors, national and international." The band follows this with an equally moving and forceful declaration of identity: "I'm proud to be an African, African like you." Shabalala and his fellow group members show that pride need not be accompanied by hate, but rather by peaceful diversity.

"Tribute," a rap in which Shabalala's grandsons nostalgically eulogize their slain grandmother, is a bit out of place on the album. The song does not feature members of Ladysmith, and seems like it might be better suited to a separate album by the band.

As a whole, Raise Your Spirit Higher is a calming, beautiful piece of music. Ladysmith Black Mambazo create a musical landscape that captivates and soothes the listener, while at the same time spreading a message of love, religion, and tolerance.