this article gives an overview of the music machines created by bosch and simons from 1990 until the present. special attention is given to vibratory projects which have been their main focus since 1993. as a consequence of physical properties – all of them being complex sprung constructions – the movements and sounds created by these machines can change almost imperceptibly from order into chaos and vice versa. the concept behind the software which controls the oscillation motors, used in this series of projects, is for the most part defined and restricted by physical conditions. this software does not dictate movement and its sonic consequences, it simply intensifies the inherent properties of the constructions. the music machines have been shown under numerous conditions which can be divided in two groups: the public vs the private space. the authors have a clear preference for the latter. this does not have to be a traditional art environment like a gallery or a museum, but at least it should be a space that offers the public a free choice to go to the exhibition. this way their work can be met with the rest and concentration needed to discover the often slow and subtle processes that take place. in the volatile atmosphere of a public space this is rarely possible.