diff --git a/src/main_osp.cc b/src/main_osp.cc
index 5ff6a30..873cf12 100644
--- a/src/main_osp.cc
+++ b/src/main_osp.cc
@@ -40,12 +40,9 @@ namespace Heck {
     Sequencer sequencer{};
 
     // function prototypes
-    void AudioCallback(
-        ld::AudioHandle::InterleavingInputBuffer in,
-        ld::AudioHandle::InterleavingOutputBuffer out,
-        size_t size);
+    void audio_callback(ld::AudioHandle::InputBuffer in, ld::AudioHandle::OutputBuffer out, size_t size);
 
-    void midi_realtime_handler(const ld::MidiEvent& msg);
+    void midi_realtime_handler(const ld::MidiEvent &msg);
 
 
     void init_tracks()
@@ -82,7 +79,7 @@ namespace Heck {
         midi.Listen();
 
         hw.PrintLine("Starting Audio");
-        hw.StartAudio(AudioCallback);
+        hw.StartAudio(audio_callback);
     }
 
 
@@ -90,10 +87,8 @@ namespace Heck {
     // RUN
     // =============================================================================================
 
-    void AudioCallback(
-        ld::AudioHandle::InterleavingInputBuffer in,
-        ld::AudioHandle::InterleavingOutputBuffer out,
-        size_t size)
+
+    void audio_callback(ld::AudioHandle::InputBuffer in, ld::AudioHandle::OutputBuffer out, size_t size)
     {
         float sig_out{};
         for (size_t i = 0; i < size; i += 2) {
@@ -101,8 +96,7 @@ namespace Heck {
                 sig_out += tracks[i].nextsample();
             }
             sig_out *= 0.1;
-            out[i] = sig_out;
-            out[i + 1] = sig_out;
+            out[0][i] = sig_out;
         }
     }
 
@@ -212,10 +206,8 @@ namespace Heck {
     {
         hw.PrintLine("Entering MainLoop");
         u32 time_boot_ms{};
-        u32 midi_log_systick_last{};
 
         bool heartbeat_led_state{ false };
-        u32 heartbeat_systick_last{};
 
         SWTimer heartbeat{};
         heartbeat.set_period(500);