The Jamhuri Jazz Band originated in the late 1950s in Tanga, Tanzania, though its original name was the Nyamwezi Jazz Band. This initial name reflected the Nyamwezi ethnic group from which most of the members or their families had come to work in Tanga, a region in the western parts of Tanzania. The early instrumentation of the band was relatively simple, featuring just two box guitars, a banjo, and a clarinet. However, by the mid-1950s or around 1966, the Tanzanian government mandated a name change due to concerns about tribalism associated with "Nyamwezi." Consequently, the group adopted the name Jamhuri Jazz Band, with "Jamhuri" being a Swahili word meaning "Republic."
The band gained nationwide popularity and was an important fixture in the East African music scene, frequently performing in Mombasa, Kenya, in addition to the Tanga Region. Jamhuri Jazz played a significant role in popularizing the Congolese Rumba sound throughout East Africa in the early 1970s. The band had notable members over the years, including the brothers Wilson Peter Kinyonga and George Peter Kinyonga, who joined the group in the late 1960s as singers, guitarists, and composers. These brothers would later leave Jamhuri Jazz in December 1970 to form the Arusha Jazz Band, which eventually evolved into the highly influential East African band, Simba Wanyika, a group responsible for numerous spin-offs in the Kenyan music scene. Jamhuri Jazz Band was managed and financed by Joseph Bagabuje, and they also featured other key musicians like John Kijiko.