This too is a requirement of art today. We need to give the spectator more room to penetrate into the work itself, and works which allow this are called ‘open’. It is a form of art that adapts itself to the artistic sense of the beholder. In times past people wanted the artist to explain in very clear terms exactly how he saw the world in every detail. The beholder was content to react to the personality of the artist, who in everyone’s eyes became a genius, the greatest, the one whom nobody could imitate. Today the person who looks at a work of art is more sensitive, more accustomed to simultaneous and intense stimuli, to brand new technical and scientific concepts, so he is no longer so interested in a ‘closed’ work of art. Art that is too defined, conclusive, and limited to one aspect of a thing, leaves a man of today standing isolated and apart: either he accepts the fait accompli or he gets nothing from it. There is very little actual participation involved. Everything that does not coincide with the particular vision of the artist has to be excluded. But in an open work of art a person participates much more, to the extent of being able to change the work of art according to his state of mind.
And, from another column on the tetracone:
The programmed art of today aims to show forms while they are in the process of becoming, and for this reason it cannot use forms such as painting and sculpture use. On the contrary, its means must be dynamic, and it must be prepared to make full use of motors and other industrial materials.
What really counts is the information which a work of art can convey, and to get down to this we have to abandon all our preconceived notions and make a new object that will get its message across by using the tools of our own time.
— Design as Art by Bruno Munari