We have defined a set of classes which reflect general concepts of composition and sound synthesis. Together with the client-server architecture they form a framework within which a complete environment for composition and sound synthesis can be built. This framework allows preexisting environments to cooperate, and provides a common ground for new tools of composition and synthesis. Its modular design allows the addition or replacement of software tools with a minimum of effort. The architecture has the additional advantage that it can be distributed over a network, and that, for example, the synthesis kernel can be run on one computer and shared between several users.