Free verse is an open form of a poetry. It does not use meter patterns, rhyme, or any other musical patterns. But, free verse still could create some structure.
It follows the rhythm of a natural speech. Free verse is an artistic expression. Free verse have been created around for hundreds of years.
After the Sea-Ship
by Walt Whitman
After the sea-ship, after the whistling winds,
After the white-gray sails taut to their spars and ropes,
Below, a myriad myriad waves hastening, lifting up their necks,
Tending in ceaseless flow toward the track of the ship,
Waves of the ocean bubbling and gurgling, blithely prying,
Waves, undulating waves, liquid, uneven, emulous waves,
Toward that whirling current, laughing and buoyant, with curves,
Where the great vessel sailing and tacking displaced the surface,
Larger and smaller waves in the spread of the ocean yearnfully flowing,
The wake of the sea-ship after she passes, flashing and frolicsome
under the sun,
A motley procession with many a fleck of foam and many fragments,
Following the stately and rapid ship, in the wake following.