Rajab Abdul Kahali (3 October 1991) is a Tanzanian musician, songwriter and dancer who goes by the stage name Harmonize. He was born in Mtwara, Tanzania. He records for music label WCB Wasafi Record, which is under Diamond Platnumz leadership. He is well known for his hit song "Bado", featuring Diamond Platnumz. He featured Rich Mavoko on his song "Show Me". He was included in MTV Base's "Ones to Watch for 2017" in Africa. Harmonize is currently managed by Joel Vicent Joseph also known as Mr Puaz and Ricardo Momo.