diff --git a/makefile b/makefile
index 10afcde..b45c68b 100644
--- a/makefile
+++ b/makefile
@@ -1,4 +1,4 @@
-SRC = src/settings.h src/fft.c src/utils_curses.c src/music_visualizer.c src/utils_mpd.c src/mt/mt19937ar.c
+SRC = src/settings.h src/fft.c src/utils_curses.c src/music_visualizer.c src/utils_mpd.c src/mt/mt19937ar.c src/beat_track.c
 LOCPATH = ./bin
 INSTALLPATH = /usr/local
 CFLAGS = -O3
diff --git a/src/beat_track.c b/src/beat_track.c
new file mode 100644
index 0000000..7ad0ed0
--- /dev/null
+++ b/src/beat_track.c
@@ -0,0 +1,77 @@
+#include "beat_track.h"
+#include "settings.h"
+
+#include <stdio.h>
+
+void cb_init(cebuffer *cb, const int capacity)
+{
+    cb->buffer = (energy_t*)malloc(capacity*sizeof(energy_t));
+    memset(cb->buffer, 0, capacity*sizeof(energy_t));
+    cb->capacity = capacity;
+    cb->count = 0;
+    cb->head = 0;
+    cb->tail = 0;
+}
+
+void cb_free(cebuffer *cb)
+{
+    free(cb->buffer);
+    cb->count = 0;
+    cb->head = 0;
+    cb->tail = 0;
+}
+
+// insert, deleting oldest element if needed
+void cb_push_back(cebuffer *cb, const energy_t item)
+{
+    // insert on head+1
+    cb->buffer[cb->head % 43] = item;
+    cb->head++;
+    if(cb->count >= cb->capacity) {
+        cb->tail++;
+    } else {
+        cb->count++;
+    }
+}
+
+unsigned int cb_avg(cebuffer *cb)
+{
+    unsigned int avg = 0;
+    unsigned int i = 0;
+
+    for(i=cb->tail; i<cb->head; ++i) {
+        avg += cb->buffer[i % cb->capacity];
+    }
+    return (int)(avg / cb->count);
+}
+
+int cb_variance(cebuffer *cb)
+{
+    double variance = 0;
+    unsigned int i = 0;
+    unsigned int avg = cb_avg(cb);
+
+    for(i=cb->tail; i<cb->head; ++i) {
+        variance += pow(cb->buffer[i % cb->capacity] - avg, 2);
+        fprintf(stderr, "head: %d, tail: %d, i: %d, buffer: %d, avg: %d\t", cb->head, cb->tail, i%cb->capacity, cb->buffer[i % cb->capacity], avg);
+        fprintf(stderr, "variance: %f\n", variance);
+    }
+    fprintf(stderr, "variance TOTAL: %f\n", variance / cb->count);
+    return (int)(variance / cb->count);
+}
+
+bool cb_beat(cebuffer *cb, const energy_t item, energy_t* energyThreshold)
+{
+    bool beat = false;
+
+    // compute the avg of the circular buffer up to now
+    *energyThreshold = (int)(-15*cb_variance(cb) + 1.55);
+
+    if(item > *energyThreshold + *energyThreshold/2) {
+        beat = true;
+    }
+
+    fprintf(stderr, "threshold: %d, item: %d\n", *energyThreshold, item);
+
+    return beat;
+}
diff --git a/src/beat_track.h b/src/beat_track.h
new file mode 100644
index 0000000..f6a58a5
--- /dev/null
+++ b/src/beat_track.h
@@ -0,0 +1,23 @@
+#pragma once
+#include <stdlib.h>
+#include <stdint.h>
+#include <math.h>
+#include <stdbool.h>
+#include <string.h>
+
+typedef unsigned int energy_t;
+
+// circular energy buffer
+typedef struct cebuffer
+{
+    energy_t* buffer;     // data buffer
+    int capacity;  // maximum number of items in the buffer
+    int count;     // number of items in the buffer
+    int head;       // pointer to head
+    int tail;       // pointer to tail
+} cebuffer;
+
+void cb_init(cebuffer *cb, int capacity);
+void cb_free(cebuffer *cb);
+void cb_push_back(cebuffer *cb, const energy_t item);
+bool cb_beat(cebuffer *cb, const energy_t item, energy_t* energyThreshold);
diff --git a/src/fft.c b/src/fft.c
index 39a4a68..a21c3d5 100644
--- a/src/fft.c
+++ b/src/fft.c
@@ -71,19 +71,6 @@
   return round(20*log10(sq)); // dB scale
 }
 
-/**
- * Not used anymore
-void
-normalize_fft(const int inLen, unsigned int* fftSig)
-{
-  int i;
-  for(i=0; i<inLen; i++){
-    fftSig[i] = (int)(10*fftSig[i]/(20*log10(fftSig[512])));
-    fprintf(stderr, "%d\n", fftSig[i]);
-  }
-}
-*/
-
 void
 fast_fft(const int inLen, uint16_t *sig, unsigned int *fftSig)
 {
@@ -135,21 +122,12 @@
 
 }
 
-void
-energy_sub_signal(unsigned int *fftBuf, int inLen, int outLen, unsigned int* fftSEnergy)
+// compute the average energy of a sample array (in amplitude form)
+void avgEnergy(unsigned int* fftBuf, const int inLen, unsigned int* energyBuf)
 {
-    // given sound amplitudes in a buffer, divide it into `outLen` subbands,
-    // compute the energy of the subband
-    // store it in fftEnergy
-    int i, k;
-    double val;
-
-    for(i=0; i<outLen; i++)
-    {
-        fftSEnergy[i] = 0;
-        for(k=outLen*i; k<outLen*(i+1); k++) {
-            val = outLen*fftBuf[k]/inLen;
-            fftSEnergy[i] += (int)(val);
-        }
+    unsigned int i;
+    for(i=0; i<inLen; ++i) {
+        *energyBuf += pow(fftBuf[i], 2);
     }
+    *energyBuf = (unsigned int)*energyBuf/inLen;
 }
diff --git a/src/fft.h b/src/fft.h
index f235aea..67b4de8 100644
--- a/src/fft.h
+++ b/src/fft.h
@@ -17,4 +17,4 @@
 unsigned int amplitude(cplx c, unsigned int n);
 void fast_fft(int inLen, uint16_t *sig, unsigned int* fftSig);
 void average_signal(unsigned int *fftBuf, int inLen, int maxC, unsigned int *fftAvg);
-void energy_sub_signal(unsigned int *fftBuf, int inLen, int outLen, unsigned int* fftSEnergy);
+void avgEnergy(unsigned int* fftBuf, const int inLen, unsigned int* energyBuf);
diff --git a/src/music_visualizer.c b/src/music_visualizer.c
index ec032ef..5d5f84b 100644
--- a/src/music_visualizer.c
+++ b/src/music_visualizer.c
@@ -14,6 +14,7 @@
 
 #include "fft.h"		// fast fourier transform
 #include "utils_curses.h"
+#include "beat_track.h"
 #include "settings.h"
 #include "mt/mt19937ar.h"
 
@@ -22,23 +23,6 @@
 #include <mpd/client.h> // status
 #include "utils_mpd.h"
 static _Atomic bool getstatus = true;
-#endif
-
-#define BEATC 25 // experiment with it
-
-static int maxR = 0;
-static int maxC = 0;
-
-#ifdef STATUS_CHECK
-void
-get_mpd_status(struct mpd_connection* session, STATUS* status)
-{
-    if(!session) {
-        session = open_connection();
-    }
-    status = get_current_status(session);
-}
-
 void
 alarm_status()
 {
@@ -46,42 +30,36 @@
 }
 #endif
 
-// TODO improve and use
-int
-test_beat(unsigned int* fftEHist, int sEnergyLen, unsigned int* sEnergy)
-{
-    int i,j;
-    for(i=0; i<sEnergyLen; i++) {
-        // shift right
-        for(j=sEnergyLen-1; j>=0; j--) {
-            fftEHist[j] = fftEHist[j-1];  
-        }
+#define BEATC 25 // experiment with it
 
-        // insert element
-        fftEHist[0] =  sEnergy[i];
-
-		// check sound energy for beat
-        for(j=0; j<sEnergyLen; j++) {
-            if (sEnergy[i] > fftEHist[j]+BEATC && sEnergy[i] < 200) { // 200 avg would be false read
-                return 1;
-            }
-        }
-    }
-    return 0;
-}
+static int maxR = 0;
+static int maxC = 0;
 
 void
 process_fifo (uint16_t* buf, unsigned int* fftBuf, unsigned int* fftAvg, \
-        unsigned int* sEnergy, int nsamples, int sEnergyLen)
+              cebuffer* energyBuffer, int nsamples, unsigned int* energyThreshold)
 {
+    // fft of samples array
     fast_fft(nsamples, (uint16_t*)buf, fftBuf);
 
     // computes an average of the signals in fftBuf
     // based on the number of columns of the screen
     average_signal(fftBuf, nsamples, maxC, fftAvg);
 
-    // compute the energy of each subband
-	energy_sub_signal(fftBuf, nsamples, nsamples/sEnergyLen, sEnergy);
+    unsigned int avg = 0;
+    if(energyBuffer->count > 0) {
+        // compute the energy of the samples array
+        avgEnergy(fftBuf, nsamples, &avg);
+        fprintf(stderr, "Computed avg: %d\n", avg);
+
+        bool beat = cb_beat(energyBuffer, avg, energyThreshold);
+        if(beat) {
+            fprintf(stderr, "BEAT!\n");
+        }
+    }
+
+    // insert the current energy sample into the circular buffer
+    cb_push_back(energyBuffer, avg);
 }
 
 void
@@ -122,12 +100,13 @@
 	int cnt = 0; // used to set resolution (wether to skip / not to skip a read)
     uint32_t sampleRate = 0;
     int nsamples = N_SAMPLES; // adapt processing to sample rate
-    int sEnergyLen = N_SAMPLES/32;
+    int sEnergyLen = N_SAMPLES;
 	PATTERN pattern = ANOTHER;
 	int statusHeight = 0;
 	int statusCol = 0;
 	bool toggleStatus = true;
     short cnt_over = 0; // in case no data is available for too much
+    unsigned int energyThreshold = 0;
 
     // add it to select() set
     FD_ZERO(&set);
@@ -136,13 +115,13 @@
     // allocate buffers used
     unsigned int* fftBuf= (unsigned int*)malloc(N_SAMPLES*sizeof(unsigned int));
     unsigned int* fftAvg = (unsigned int*)malloc(N_SAMPLES*sizeof(unsigned int));
-    unsigned int* fftEHist = (unsigned int*)malloc(sEnergyLen*sizeof(unsigned int));
-    unsigned int* sEnergy = (unsigned int*)malloc(sEnergyLen*sizeof(unsigned int));
+    cebuffer energyBuffer;
+
+    cb_init(&energyBuffer, 43);
+
 	// set the result buffer to 0s
     memset(fftBuf, 0, N_SAMPLES*sizeof(unsigned int));
     memset(fftAvg, 0, N_SAMPLES*sizeof(unsigned int));
-    memset(fftEHist, 0, sEnergyLen*sizeof(unsigned int));
-    memset(sEnergy, 0, sEnergyLen*sizeof(unsigned int));
 
     // open connection to mpd and set alarm to refresh status
 #ifdef STATUS_CHECK
@@ -194,7 +173,7 @@
             ret = read(fifo, (uint16_t*)buf, 2*nsamples);
             // process read buffer
 			if(cnt == NICENESS) {
-            	process_fifo(buf, fftBuf, fftAvg, sEnergy, nsamples, sEnergyLen);
+            	process_fifo(buf, fftBuf, fftAvg, &energyBuffer, nsamples, &energyThreshold);
 				cnt = 0;
 			} else {
 				cnt++;
@@ -251,11 +230,10 @@
 #endif
     free(fftAvg);
     free(fftBuf);
-    free(fftEHist);
-    free(sEnergy);
+    //    cb_free(&energyBuffer);
     close(fifo);
-    if(cnt_over) return 1;
 
+    if(cnt_over) return 1;
 	return 0;
 }
 
diff --git a/src/settings.h b/src/settings.h
index fd66ae9..56fef15 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -78,8 +78,8 @@
 // adjust lateral shift on screen
 // some optimal values are provided
 // adjust based on terminal dimensions
-#define X_CORRECTION 1   // 1280x1024 screens (5:4)
-//#define X_CORRECTION 8 // 1920x1080 screens (16:9)
+/* #define X_CORRECTION 0   // 1280x1024 screens (5:4) */
+#define X_CORRECTION 8 // 1920x1080 screens (16:9)
 
 /* =========== ALSA Support (WIP) ============ */