There is a special place that is beyond the grasp of mere music, where experience and will and even travail all combine to make the notes more than just frequencies, and the lyrics more than just words.

There are not many acts that traffic in this kind of music – the Gyuto Monks and the Blind Boys of Alabama come to mind immediately, as does Ladysmith Black Mambazo, the long-running South African vocal group that performed at Bass Performance Hall on Monday night.

Whereas listening to the Monks is like staring through a hole in the universe, and the Blind Boys have a biblical weight to their singing, LBM is all the more amazing for how sunny and positive their music is.

They proved that Monday for about 1,500 enthusiastic fans, deploying their incredibly tight harmonies and impeccable choreography like the cultural emissaries they professed themselves to be.

Their sound will be familiar to anyone who remembers Paul Simon's Graceland, the 1986 album that introduced them to the West and (arguably) midwifed the world music revolution.

The format of their songs is remarkably consistent: Longtime leader and founder Joseph Shabalala usually solos, as his cohorts cushion his leads with billowing clouds of harmony.

The first song, "Baleka Mfana," meant – appropriately enough – "Hello," a message that the nine-man troupe made obvious with sweeping, precisely synchronized movements of their arms. They seemed to have an infinite array of these asides – grabbing their belts, fluttering their hands at their sides like birds, or high kicking like cheerleaders.

One might be tempted to continually think of them in political terms. After all, "Long Walk to Freedom" had definitely taken struggle and determination as its subject matter, and "Nginethemba" was introduced as a song "to encourage people to come together and solve their problems."

That's what makes Ladysmith Black Mambazo so delightful: Where others might descend into preaching and polemic, they can just as easily visit the world's lighthearted places.

After all, "Nomathemba" (an early song from 1964) is about a crush, just like any other pop song. "Hello My Baby' (not the barbershop-quartet chestnut) had definite doo-wop accents and featured a recurring "Kiss me!" line that never failed to get a giggle.

Another aspect to a band ascending to that higher level is continuity, and – as Mr. Shabalala noted – four of the current members are his sons. Mr. Shabalala recently announced that he would retire this year; Thamsanqa, who sang a rhythmic "Ekuhlupekeni," is widely regarded as the heir apparent.

Seldom does so much gravitas come with such a wide grin. Monday night at Bass Hall, the music of Ladysmith Black Mambazo seemed as enjoyable as it was important.

-- by Matt Weitz