You probably know their sound even if you don’t know the group’s name. You wouldn’t forget this chorus of voices rising and falling like mountains on the horizon, inextricably linked and moving as one but full of individual cries and whispers, swooping from the lowest bass note to precariously high peaks. Their singing is a shimmering, undulating, emotional wave that can make a listener gasp or cry or simply luxuriate in the sound. They are Ladysmith Black Mambazo, a choral group from South Africa that sings isicathamiya and mbube, two traditional Zulu-rooted vocal styles that date back to the turn of the 20th century.

The group most famously appeared on Paul Simon’s 1986 album Graceland, lending their stunning acapella vocals to the impossibly beautiful “Homeless,” and also appearing on “Diamonds on the Soles of Her Shoes” among other tracks. By the time they recorded with Simon, however, they’d been together in one form or another since 1960. The group’s founder and leader, Joseph Shabalala, worked with his original group, called Ezimnyama, until 1964, when a vision of a new group came to him in a dream: His family, singing in a kind of perfect harmony he’d never achieved.

He recruited his cousin Albert Mazibuko as a tenor vocalist in 1969, and over the course of the next three decades added four of his sons to the group, recording over 50 albums and winning four Grammy Awards along the way. “We believed in Joseph,” Mazibuko says. “Other people didn’t. They said he was crazy. But we believed in him, and he relied on us. When he came to me, he had dreamt of his grandmother, telling him, ‘Go to your brothers, they will help you, they will listen to you.’ We respected him and said, ‘Whatever you do, we will do exactly what you want us to.’ In our culture, you listen to your elders. So, it became a family group, and now we are joined by our sons. It’s a family affair.”

Ladysmith added another Grammy nomination this year for their newest album, Walking in the Footsteps of Our Fathers. It was their first ever album without Joseph Shabalala; the much-beloved leader and mentor retired at the age of 75 before it was recorded. “It was time for him to sit down and enjoy what he has done,” Mazibuko says. “If we’re doing performances in certain places, sometimes he will come and sit and watch us, and you can see him singing with us sometimes. He’s enjoying himself.”

But the Ladysmith elders have spent decades teaching the younger members the traditions, songs, and dances of their past. “There was no change because we made sure the young guys were following in our footsteps,” Mazibuko says, echoing the album’s title. “We have been with them for some time now, 23 years in the group for most of them, so they know everything about the group. Now is their time to ensure the music we created and the legacy we are leaving for them. So this album speaks for them.”

The album is an interesting mix of redone classics like “Homeless” and “Long Walk To Freedom,” their mesmerizing and haunting retelling of the end of apartheid, and new songs written by some of the group. “The style and the message are the same,” he says. “But they put something in that sound from themselves, and they did a very good job.”

There are many emotional performances on the album, from the hard-earned emergence from oppression on “Long Walk to Freedom” to the romantic yearning of “Paulina” to the message of devotion in “Because I Love You.” No matter the subject, there’s feeling in Ladysmith’s singing — the voices endlessly, perhaps surprisingly, optimistic. “Ladysmith Black Mambazo music was made to give people a positive message,” Mazibuko says. “It was made to encourage them to be strong, and empower them. When we established this group, we made sure the music we sing was empowering people. You experience tough times, but they don’t stay forever. You have to be strong to be able to go through those times. That’s the mission of Ladysmith Black Mambazo. That is our message.”

To reinforce this, Mazibuko tells a story of his youth, and like his group’s music, it takes in pain and sorrow, faith and happiness. “We learned from our childhood that singing is a powerful force behind everything,” he says. “We grew up on the farm. Things were not easy on the farm. I remember sometimes we’d wake up in the morning during the winter, and we would work barefoot in the snow.”

He pauses for a few moments, seemingly lost in the memory. “Just imagine how cold that was,” he continues. “But what I found was that everybody on the farm was singing just to empower our souls and to numb that pain that we were feeling. The music makes you keep going. It’s something that we realized: The music is so powerful.”