Composition and diffusion can be understood as two complementary and related processes: bringing sounds together, and spreading them out again in an organised fashion. In the Western tradition, these two processes are frequently carried out by different people at different times, each drawing on specialised knowledge. The electroacoustic tradition, even if much briefer, offers the possibility of the composer designing and implementing both aspects of the music, and interrelating them in highly specific ways. Computer control offers the greatest precision in dealing with the complexities of these processes, even though, at present, separate programs are usually required.