diff --git a/src/forge.c b/src/forge.c
index c82b2c8..be6923a 100644
--- a/src/forge.c
+++ b/src/forge.c
@@ -203,9 +203,8 @@ static void key_callback(Window *window, int key,
 }
 
 static void midi_callback(unsigned char code, float value) {
-  log_debug("midi: %d %.2f", code, value);
-  midi_write(midi, code, value);
-  // TODO treat in state file
+  state_apply_event(context, state_config, program.frag_count, midi, code,
+                    value);
 }
 
 static void loop(bool hr) {
@@ -268,6 +267,10 @@ void forge_run(Parameters params) {
     if (!midi_background_listen(midi, context, midi_callback)) {
       return;
     }
+
+    if (!state_background_midi_write(context, state_config, midi)) {
+      return;
+    }
   }
 
   window_startup(error_callback);
diff --git a/src/shaders.c b/src/shaders.c
index f559797..3fff416 100644
--- a/src/shaders.c
+++ b/src/shaders.c
@@ -2,7 +2,6 @@
 #include <log.h>
 #include <stddef.h>
 #include <stdio.h>
-#include <stdlib.h>
 
 #include "config.h"
 #include "config_file.h"
diff --git a/src/state.c b/src/state.c
index 8630ec1..9f835ee 100644
--- a/src/state.c
+++ b/src/state.c
@@ -1,7 +1,10 @@
-#include "state.h"
+#include <log.h>
+
 #include "config.h"
 #include "config_file.h"
+#include "midi.h"
 #include "rand.h"
+#include "state.h"
 #include "types.h"
 
 StateConfig state_parse_config(ConfigFile config) {
@@ -92,6 +95,38 @@ StateConfig state_parse_config(ConfigFile config) {
   return state_config;
 }
 
+void state_apply_event(SharedContext *context, StateConfig state_config,
+                       unsigned int state_count, MidiDevice midi,
+                       unsigned char code, float value) {
+  log_debug("midi: %d %.2f", code, value);
+  midi_write(midi, code, value);
+  // TODO
+}
+
+bool state_background_midi_write(SharedContext *context,
+                                 StateConfig state_config, MidiDevice midi) {
+  pid_t pid;
+  int bytes_read;
+  unsigned char buffer[3];
+
+  pid = fork();
+  if (pid < 0) {
+    log_error("Could not create subprocess");
+    return false;
+  }
+  if (pid == 0) {
+    return true;
+  }
+  log_info("(state) background writing started (pid: %d)", pid);
+
+  while (!context->stop) {
+    // TODO tap tempo and more
+  }
+
+  log_info("(state) background writing stopped by main thread (pid: %d)", pid);
+  return false;
+}
+
 void state_randomize(SharedContext *context, StateConfig state_config,
                      unsigned int state_count) {
   unsigned int i;
diff --git a/src/state.h b/src/state.h
index f7f4e6d..2c12452 100644
--- a/src/state.h
+++ b/src/state.h
@@ -5,6 +5,13 @@
 
 StateConfig state_parse_config(ConfigFile config);
 
+void state_apply_event(SharedContext *context, StateConfig state_config,
+                       unsigned int state_count, MidiDevice midi,
+                       unsigned char code, float value);
+
+bool state_background_midi_write(SharedContext *context,
+                                 StateConfig state_config, MidiDevice midi);
+
 void state_randomize(SharedContext *context, StateConfig state_config,
                      unsigned int state_count);