Rajabu Abdul kahali was born in Cbitoholi, Mtwara province Tanzania on 15th March 1991. He came from a poor family and to make ends meet. Harmonize needed to try anything and everything to escape the poor life he grew up in. He started selling tea in Kariokor market just so that he was able to put food on table. He started his music career in 2015 he released 'Ayiola' a sunny and melodic single followed by 'Bado' in 2016 whereby he collaborated with fellow Tanzanian Diamond Platinum in 2017 he released other single including g"Happy birthday '' 'Sina' and kwa Ngaru'' again with Diamond Platnumz that served as his breakthrough hit. He was the first artist to sign a recording contract with Diamond Platnumz WCB wasafi label. He has won three awards from wastsUp TV, AFRIMMA and AEA USA ( in the US). In 2018 je launched his own label, Conde music worldwide and collaborated with artists like sheebah, Eddy Kenzo and Phyno before delivering his debut full length , AfroEast in 2020. Harmonize left WSB wasafi in the end of 2019 and released several projects including the '' return of Q chillah''
In 2019 Harmonize married Italian socialite and entrepreneur, Sarah Michellotti but in 2020 one year after exchanging vows, it was announced that the couple had separated due to irreconcilable differences caused in part by infidelity on the side of Harmonize which him to fathering his first child out of wedlock. Just months later he entered in a new relationship wit Thanzanian actress Friday Kalaja Masanja.