diff --git a/main.cpp b/main.cpp
index 199c71e..86d6609 100755
--- a/main.cpp
+++ b/main.cpp
@@ -25,15 +25,20 @@ int current_instrument = 0;
 int current_volume = 2;
 int current_effect = 0;
 
-toneGen tonegen(SOUND_NUM_SAMPLES);
+toneGen channel[4];
 SDL_AudioDeviceID sdlAudioDevice;
+Sint16 auxBuffer[512];
 
 void audioCallback(void* userdata, Uint8* stream, int len) {
     Sint16* buffer = (Sint16*)stream;
-    int numSamples = tonegen.getSamples(len >> 1, buffer);
-    if (numSamples*2 < len) {
-        int rest = len - numSamples*2;
-        SDL_memset(&stream[numSamples*2], 0, rest);
+    int numBytesGenerated = channel[0].getSamples(len >> 1, buffer) * 2;
+    for (int i=1; i<4; ++i) {
+        channel[i].getSamples(len >> 1, auxBuffer);
+        for (int j=0; j<numBytesGenerated; ++j) buffer[j] += auxBuffer[j];
+    }
+    if (numBytesGenerated < len) {
+        int rest = len - numBytesGenerated;
+        SDL_memset(&stream[numBytesGenerated], 0, rest);
         SDL_PauseAudioDevice(sdlAudioDevice, 1);
     }
 }
@@ -46,6 +51,7 @@ const char get_hex(const uint8_t num) {
 }
 
 int main(int argc, char* argv[]) {
+    for (int i=0; i<4; ++i) channel[i].setNoteLength(SOUND_NUM_SAMPLES);
     pattern[0][0] = (34<<10) + (2<<8) + (7<<4) + 5;
     SDL_Init(SDL_INIT_EVERYTHING);
     sdlAudioDevice = SDL_OpenAudioDevice(NULL, 0, &audioSpec, NULL, 0);
@@ -157,7 +163,10 @@ int main(int argc, char* argv[]) {
                 //uint8_t base_note = 1+(base_octave-2)*12;
                 if ((key == SDL_SCANCODE_PERIOD) || (key == SDL_SCANCODE_DELETE)) note.Set(0);
                 if (key == SDL_SCANCODE_SPACE) {
-                    tonegen.setup(note.Get());
+                    channel[0].setup(pattern[0][selected_row]);
+                    channel[1].setup(pattern[1][selected_row]);
+                    channel[2].setup(pattern[2][selected_row]);
+                    channel[3].setup(pattern[3][selected_row]);
                     SDL_PauseAudioDevice(sdlAudioDevice, 0);
                 }
                 if (selected_part==0) {
@@ -178,7 +187,7 @@ int main(int argc, char* argv[]) {
                         default: m = false; break;
                     };
                     if (m) {
-                        tonegen.setup(note.Get());
+                        channel[0].setup(note.Get());
                         SDL_PauseAudioDevice(sdlAudioDevice, 0);
                     }
                 }
diff --git a/tonegen.cpp b/tonegen.cpp
index 83d9e10..48ff1c2 100755
--- a/tonegen.cpp
+++ b/tonegen.cpp
@@ -4,8 +4,7 @@
 
 Sint16 notes[64];
 
-toneGen::toneGen(const int note_length) {
-    this->note_length = note_length;
+toneGen::toneGen() {
     this->current_pos = 0;
 
     this->note = 34;
@@ -24,6 +23,10 @@ toneGen::toneGen(const int note_length) {
     this->f = -AUDIO_FORMAT_MAX_VALUE;
 }
 
+void toneGen::setNoteLength(const int note_length) {
+    this->note_length = note_length;
+}
+
 void toneGen::setup(const uint8_t note, const uint8_t instrument, const uint8_t volume, const uint8_t effect) {
     this->current_pos = 0;
 
diff --git a/tonegen.h b/tonegen.h
index ddc3f44..e6c9878 100755
--- a/tonegen.h
+++ b/tonegen.h
@@ -16,7 +16,8 @@
 
 class toneGen {
     public:
-        toneGen(const int note_length);
+        toneGen();
+        void setNoteLength(const int note_length);
         void setup(const uint8_t note, const uint8_t instrument, const uint8_t volume, const uint8_t effect);
         void setup(const uint16_t tracker_note);
         const int getSamples(const int numSamples, Sint16 *buffer);