I've patched together some of the minim examples to achieve what I thought would be real-time audio reactive animation. I have the "kick, snare, hat" example (beatListener) open that I've modified with the AudioRecord example so that instead of kick,snare, and hat responding to a playing .mp3 file, they respond to the live record stream on my PC.

My attempt at the most obvious solution comes up to swap the 'song' variables with the 'line in' values produces the error "Line 23: The constructor AudioResponse.BeatListener(BeatDetect, AudioInput) is undefined" - which I've come to determine is because AudioInput is the wrong kind of value to be passed to BeatListener. 

2. 
   
3. import ddf.minim.*;
4. import ddf.minim.analysis.*;
5. 
   
6. Minim minim;
7. 
   
8. BeatDetect beat;
9. BeatListener bl;
10. AudioInput in;
11. float kickSize, snareSize, hatSize;
12. 
    
13. void setup()
14. {
15.   size(512, 200, P3D);
16.   
17.   minim = new Minim(this);
18.   in = minim.getLineIn(Minim.STEREO, 2048);
19.   beat = new BeatDetect(in.bufferSize(), in.sampleRate());
20.  
21.   beat.setSensitivity(300);  
22.   kickSize = snareSize = hatSize = 16;
23.   bl = new BeatListener(beat, in);  
24.   
25.   textFont(createFont("Helvetica", 16));
26.   textAlign(CENTER);
27. }
28. 
    
29. void draw()
30. {
31.   background(0);
32.   fill(255);
33.   if ( beat.isKick() ) kickSize = 32;
34.   if ( beat.isSnare() ) snareSize = 32;
35.   if ( beat.isHat() ) hatSize = 32;
36.   textSize(kickSize);
37.   text("KICK", width/4, height/2);
38.   textSize(snareSize);
39.   text("SNARE", width/2, height/2);
40.   textSize(hatSize);
41.   text("HAT", 3*width/4, height/2);
42.   kickSize = constrain(kickSize * 0.95, 16, 32);
43.   snareSize = constrain(snareSize * 0.95, 16, 32);
44.   hatSize = constrain(hatSize * 0.95, 16, 32);
45. }
46. 
    
47. void stop()
48. {
49.   // always close Minim audio classes when you are finished with them
50.   song.close();
51.   // always stop Minim before exiting
52.   minim.stop();
53.   // this closes the sketch
54.   super.stop();
55. }