diff --git a/code/project/main.py b/code/project/main.py
index 16eac96..3dd86d3 100644
--- a/code/project/main.py
+++ b/code/project/main.py
@@ -33,10 +33,12 @@ images_set = {
 loop: bool = True
 tone: bool = False
 midi_key: int = 69
+tone_mode: bool = True
 
 
 # Fetch the base image for the note letter from the global dictionary,
 # Then embellish it with the octave pattern (in binary) and potential flat flag
+# Flat flag goes in the bottom right pixel at partial brightness, and binary octave pattern goes from top right down
 def get_image(note_letter: str, octave: int) -> Image:
     base_letter = note_letter[0]
     base_img = images_set[base_letter]
@@ -56,11 +58,12 @@ def get_image(note_letter: str, octave: int) -> Image:
             base_img.set_pixel(4, i, 0)
     return base_img
 
-
+# Example: get_note(69) -> ("A", 4)
 def get_note(key: int) -> tuple:
     return ((note_names[key % 12]), ((key // 12) - 1))
 
 
+# Logic controller for the speaker. Decides when to start and stop, and looks up which note to play
 def manage_tone(midi_key):
     global tone
     if pin_logo.is_touched() and tone == False:
@@ -73,6 +76,7 @@ def manage_tone(midi_key):
         tone = False
 
 
+# Logic controller for the display
 def manage_display(midi_key):
     note = get_note(midi_key)
     note_letter = note[0]
@@ -85,8 +89,9 @@ def log():
     print(midi_key, "-", note[0], "[", note[1], "]")
 
 
-manage_display(midi_key)
-while loop:
+# Logic for "tone mode" - Pick a note and play it
+def tone_mode_controller():
+    global midi_key
     input = (button_a.was_pressed(), button_b.was_pressed())
     update = False
     if input == (False, False):
@@ -103,4 +108,23 @@ while loop:
         log()
         manage_display(midi_key)
     manage_tone(midi_key)
+
+
+# Stub logic for listen mode. See README.md for elaboration
+def listen_mode_controller():
+    # mic_in = pin5.get_pull()
+    # mic_run = pin20.get_analog_period_microseconds()
+    display.show(Image.CONFUSED)
+
+
+# Main Program Logic. Run the display once before looping
+manage_display(midi_key)
+while loop:
+    if button_a.is_pressed() and button_b.is_pressed():
+        tone_mode = not tone_mode
+        sleep(100)
+    if tone_mode:
+        tone_mode_controller()
+    else:
+        listen_mode_controller()
     sleep(100)