Solomon Murungu has just finished giving a presentation on the mbira, a musical instrument of the Shona people in his home country of Zimbabwe. During the hourlong event, he'd explained to the group of about 20 people gathered in a conference room at the Cambridge Citywide Senior Center on Massachusetts Avenue that the instrument made of wood and iron is used by the Shona to communicate with their ancestors. He described the significance of different parts of the instrument. Then he used his fingers to pluck a few traditional songs, which lilted in the air in soothing, dulcet tones, giving listeners a taste of the music. Now the audience is asking questions. Do the instrumental songs he played have words? They do, Murungu answers, but he doesn't sing. What parts of his hands are used to play the instrument? A combination of nails and the fleshy parts of his fingers. In fact, the instrument is so hard on his hands, he tells them, that Murungu regularly gets a manicurist to apply acrylic nails on his thumbs and right index finger to protect them. Elena Lindor , 73 , a Cambridge resident who visited Zimbabwe's Victoria Falls last November, wonders if the mbira is taught in schools in Zimbabwe. No, says Murungu, it is not. Zimbabwe's indigenous people suffered under British colonial rule from the 1890s to the 1970s in a system similar to apartheid in South Africa. Under the British, the Shona people had to reject their traditional ancestor worship and embrace the Church of England. Today indigenous Africans remain reluctant to embrace this part of their culture. Murungu offers this presentation under Zambuko Projects Unlimited , an organization he started in 1994 to educate Americans about Zimbabwe an culture, particularly the mbira. Under the auspices of Zambuko, Murungu offers educational talks for students from elementary school to college; mbira demonstrations and workshops; and spiritual services that allow Westerners to experience ancestor worship. Murungu created the business, which he operates when he's not at his day job as a computer engineer at Upromise Inc. in Needham, after giving several talks to students at the Charlotte Dunning Elementary School in Framingham, as a part of parent/student presentations when his two daughters, Pepukai , 19, and Simukai , 17, and son, Shingira , 15, attended the school. As he spoke to his children's peers and to his own acquaintances , Murungu discovered that Americans had many misconceptions about Africa. "A lot of people . . . still have that sort of Tarzan mentality about the continent," says Murungu, 51, who lives in Bolton. "They think that people live in trees and huts. When you tell them there are cities in Africa, they actually get very surprised." In Murungu's mind, Zambuko can help break the barriers and show how many things the American and African cultures have in common. He calls his organization Zambuko because the word means "bridge" in the Shona language.