Rei was a member of Boston based Cape Verdean rap group BM (Bullet Movement) together with Stash Loso, Individual and Filinto performing with lyrics in Cape Verdean Creole and releasing their first mix-CD "CV's Most Wanted" in 2002 followed by the release of "Streets Wanted It" a year later. The groups second mix-CD featured songs "Li Na Boston", "Nha Talento" and "Batida" which were well received among the Cape Verdean community. In 2005 Chuku Brutu, and Zezito aka Grogu joined the group ahead of their third mix-CD "3 Stripes" which was released that same year, with the lead single "Mexi Bunda" reached number on Cape Verdean national radio station PraiaFM.
In 2008, the group members decided to release solo projects, with Rei Assa releasing "Cimiterio Vol. 1" vol. 1 was released. In 2009, Rei teamed up with Ildo Depina, who was in the process of forming the music label Lo Records, where he released his debut album "Sr. Tavares" on November 7th, 2009 "Sr. Tavares" was released. The album featured acclaimed singles "Bo e Boa", "Dorchester, Roxbury", "Mama" and "Nos Cultura, Nos Terra".