In the past few years of the development in the field of electro-acoustic applications, it turned out that new input and output options are needed to make a convenient control of technical and aesthetical processes possible. This particularly holds for live performances. As a consequence thereof, several different hard- and software developments emerged recently. Many of them are closely related to general improvements of the computational industry (such as mouse or joystick), others have been developed for a particular occasion, such as for a certain artist, a performance, or a concert. This paper investigates the potential effects of these new developments for musical applications. The paper is organized as follows: Starting from a description of interactive computer music systems, I will introduce Gestalttheoretical concepts in order to allow for a characterization of the basic properties of these systems. Thereafter I will apply them to the interaction of man and music systems. Gestalt concepts will be introduced to describe this interaction. Finally, I will illustrate the criteria I am going to set up in this paper, taking a dataglove sound synthesis configuration as an example of such a system.