In 2000, Don Jazzy visited London. His uncle had invited him to play the drums for the local church. In London, Don Jazzy gained employment at McDonald’s as a security guard. He continued his interest in music, associating with Solek, JJC, Kas, The 419 Squad and D’Banj.

In 2004, Don Jazzy collaborated with D’Banj to form Mo’ Hits Records. In the next two years, Don Jazzy produced the albums No Long Thing and Rundown/Funk You Up. A third album, Curriculum Vitae, had also been started. Around this time, Don Jazzy developed a recognisable introduction, “It’s Don Jazzy Again!”

In 2008, Don Jazzy was credited in the production of The Entertainer by D’Banj. He also contributed to the production of Wande Coal’s Mushin 2 MoHits, an album that was described as one of the best albums to ever come out of Nigeria.

In 2011, Don Jazzy was employed by Kanye West as a producer at Very Good Beatz. Don Jazzy worked with Jay-Z and Kanye West on the production of Lift Off, featuring Beyoncé on the album Watch The Throne which was released on 8 August 2011.

In March 2012, Don Jazzy and D’Banj confirmed their breakup citing artistic differences.

On 7 May 2012, Ajereh announced a new record label, Mavin Records. Ajereh said, “I see Mavin Records being the power house of Music in Africa in the shortest possible time.” On 8 May 2012, he released an album featuring the artists signed to his label. The songs on the album included: Amarachi, Forever, Oma Ga, Take Banana and Chocolate, YOLO and the anthem I’m a MAVIN. Mavin records signed the vocalist, Tiwa Savage. Ajereh built a social network platform called “Marvin League” to complement and market his label.

In 2012, Ajereh appeared in Moses Inwang’s movie The Last 3 Digits in Nollywood. Inwang also cast Ali Baba, A.Y., Nonso Diobi and Dr. Sid.

On 5 November 2013, Ajereh had conflict with an artist, Wande Coal who left the label two days later.

In September 2014, Ajereh produced a Nigerian social activist song with Reekado Banks and Di’Ja called Arise.