Master Joe (Puerto Rican) (Joel Hernández Rodríguez) and O.G. Black (Dominican) (Adolfo Ramírez) are a Dominican–Puerto Rican reggaeton duo. They have released various albums and spawned moderate hits in Puerto Rico. They were part of DJ Joe's Escuadron Del Panico along with Hakeem & Jenay, Ranking Stone, Genio, Guayo Man, Doble Impact, Trebol Clan, and DJ Joe. As of 2007, they are no longer a duo. Master Joe duos with Lil' Sean. O.G. Black duos with Guayo Man. O.G. Black used to duo with Q Mac Daddy in the mid 90s and they released the CD Bajo Tu Observación.