In setup set y=width;

Thanks a lot, Chrisir,

still try to understand what should go where. it's still two complicated for me sorry :( Probably it's messy because because i'm just amending the excising coding which originally looked different...

if you could explain more about where in my code i shall put this 'setup y=width'

and also do you mean it's messy here:

1.  float x1 = track.right.get(i)*column_width/2 + (column_norm);
       float x2 = track.right.get(i+1)*column_width/2 + (column_norm);
       float y1 = height - y/vertical_scaling;
       float y2 = height - (y+1)/vertical_scaling;
   

if you please can explain a little bit more it would be great.

Thanks a lot.

When you define y you have (Sorry, it's after setup() ) float y=0; And later y--;

Thanks, Chrisir,

unfortunately it doesn't turn the graphic. It's only a black screen instead.

If you're be able to check it later I'll be very grateful.
Thanks for your recommendations I'll try to do what I can.
Have a lovely journey.

I dunno how you want it,
now it goes from bottom to top and then from left to the right.

1. import ddf.minim.*;
2. // import processing.opengl.*;
3. AudioPlayer track;
4. Minim minim;
5. void setup()
6. {
7.   size(600, 700);
8.   background(0);
9.   stroke(255);
10.   smooth();
11.   minim = new Minim(this);
12.   track = minim.loadFile("info.mp3", 2048);
13.   track.loop();
14. }
15. float bpm = 50.2;
16. float mspb = 60000/bpm;
17. float x = 0;
18. float y = 0;
19. float vertical_scaling = 160;
20. float column_width = 7;
21. int time = 0;
22. void draw()
23. {
24.   int lapse = millis() - time;
25.   for (int i = 0; i < track.left.size()-1; i++)
26.   {
27.     float column_norm = column_width/2*(1+1.5*x);
28.     float x1 = track.left.get(i)*column_width/2 + (column_norm);
29.     float x2 = track.left.get(i+1)*column_width/2 + (column_norm);
30.     float y1 = height - y/vertical_scaling;
31.     float y2 = height - (y+1)/vertical_scaling;
32.     line(x1, y1, x2, y2);
33.     y++;
34.   }
35.   if (lapse > mspb)
36.   {
37.     time = millis();
38.     x++;
39.     y = 0;
40.     if ((x+1)*column_width > width)
41.     {
42.       x = 0;
43.       background(0);
44.     }
45.   }
46. }
47. void stop()
48. {
49.   // always close Minim audio classes when you are done with them
50.   track.close();
51.   minim.stop();
52.   super.stop();
53. }

Dear Chrisir, you are simply a LEGEND, nothing more nothing less. Many thanks for your help. it works exactly the way i need it.

thank you!
Glad to hear that!