One of my old sketches

float x1,y1,x2,y2,x3,y3,x4,y4;
float MODIFIER;
boolean recording = false;


void keyPressed() {
  if ( key == 'r' || key == 'R') {
    recording = !recording;
  }
}


void setup() {
 size( 1000, 1000 );
 smooth();
 noFill();
 background( 255, 255, 255, 100 );
 strokeWeight( 0.1 );


 x1 = 0;
 y1 = 10;
 x2 = 470;
 y2 = 90;
 x3 = 600;
 y3 = 7;
 x4 = 1000;
 y4 = 30;
 
 MODIFIER = 1000;
}


void draw () {
 float t = frameCount / 100.0;
 
 for ( int i = 1; i < 3; i++ ) {
   bezier( x1, y1 , noise( 2 , i, t )* MODIFIER, noise( 3 , i, t )*MODIFIER, noise( 4 , i, t )* MODIFIER, noise( 5 , i, t )* MODIFIER, x4, y4 );
   y1+=0.5;
   y2+=1.5;
   y3+=1.5;
   y4+=0.5;
   stroke( 25, 25, 25 );
 } 
 
     if ( recording ) {
      saveFrame("output/bezier_####.png");
    } else {


    }
 
 
}

Video output: