• Single moving semi-transparent line
• Aggregate drawing (aka no background call)

Below is a basic example of this technique. Obviously it can be much further tweaked.

Code Example

1. int numPoints = 5;
2. float x, speed = 0.05;
3.  
4. void setup() {
5.   size(1200, 400);
6.   background(0);
7.   frameRate(2000);
8.   noFill();
9.   stroke(255, 5);
10. }
11.  
12. void draw() {
13.   float fc1 = frameCount*0.0005;
14.   float fc2 = frameCount*0.001;
15.   if (x<0) { speed = abs(speed); }
16.   if (x>width) { speed = -abs(speed); }
17.   x += speed;
18.   beginShape();
19.   curveVertex(x, 0);
20.   for (int i=0; i<numPoints; i++) {
21.     float xp = x+sin(i+fc2)*100;
22.     float yp = noise(i+fc1)*height;
23.     curveVertex(xp, yp);
24.   }
25.   curveVertex(x, height);
26.   endShape();
27. }