This music is inspired by events that have their own internal rhythm, harmony and melody and which only occur once. They begin at one point in time and end at another, never to repeat in exactly the same away again: autumn leaves blowing in a brisk wind, clouds continually changing shape in the sky, a tornado making a path through a small town, Jackson Pollock painting one of his drip paintings, the life of every single human being, dog or cat or tree.
More traditional music is bound by time signature and key signature. It is written down with the expectation that it will be played again according to the notation. There is a right way and many wrong ways to play it. This makes it authoritarian. When rock music is played at a concert, most people will feel the same beat and start moving with it. Individuals begin to move as one unit. There is no such structure to this music. The listener cannot predict the beat or harmonic movement in the way they can with traditional forms.
Just sit back and listen as you would to a bunch of birds singing in the woods, a storm coming, the wind in the trees or the roar of a crowd at at football game. Much of our world plays like this.