Gangrene is an American, California-based hip hop/production duo, which consists of rapper/producers The Alchemist and Oh No. The Alchemist and Oh No, MCs and producers in their own right, weren't acquainted until they met at a show headlined by Dilated Peoples member and mutual friend, Evidence. The Alchemist contacted Oh No and proposed a collaborative project. From that point they "just clicked," says Oh No. "I sent him a verse and a beat, and he sent a beat and a verse." The creative sparring continued, and they began to refer to the work as Gangrene.

In 2013, Gangrene, Tangerine Dream and Woody Jackson scored the original score for Grand Theft Auto V by Rockstar Games.