Most video gamepublishing companies, such as Electronic Arts, Activision, and Sony, do maintain development studios, but these companies are generally called "publishers" and not "developers", as publishing is the primary activity of these companies, and is the source of most of their income.
Rather confusingly the publishers themselves are sometimes referred to as third-party developers in the context of their relationships with the console manufacturers (Sony, Microsoft and Nintendo).
Game developers, especially newer ones, have a reputation for allowing excess enthusiasm for a project to override good sense, with reality as to the immense amount of work that has been taken on setting in after the commercial schedule has already been decided.
Games, like movies, now use a music supervisor whose job is to identify and source music that will be added to the soundtrack of each game.
If the gamepublisher decides it does not have the interest, means, or staff to manage its catalog of musical copyrights, there are resources available to take on the responsibility.
As the games industry grows, as games are advertised more and more on television, as game properties are licensed to become movies, and as exposure of games increases through electronic media, music and exploitation of music from games can begin to generate meaningful revenue.