The unfolding of the work of art in space-time of life can be seen in many modern and contemporary avant garde works. The completion of these works takes place in the simultaneity of events in the world, being chance and uncertainty key elements in the outcome of the work. Thus, the artwork is open to the field of possibilities to the randomness of tangible reality, and its shape in a constant change. The meanings, then, established themselves in the multitude of events, where the desire to have a closed form is dissolved in constant becoming. And that makes these works an event, due to its realization on the surface of spatiality-temporality. From Musique d ameublement of Erik Satie, circa 1917-1920, and Untitled (Mirrored Cubes) by Robert Morris, 1965, we will try to understand the concept of event introduced by these two works, as will be discussed that concept triggered by other artists, which somehow relate to the two cited, for example, John Cage. And being the music of Satie made to be played in environments belonging to daily life, between conversations and actions occurring, and the mirrored cubes of Morris occur during the experience of the observer, while circling, art is performed, then, as an event in which its developments now are subject to chance.