Update app.py

app.py

@@ -173,32 +173,58 @@ SORTED_QUALITIES = sorted(CHORD_INTERVALS.keys(), key=len, reverse=True)
 
 def parse_chord_to_midi(chord_string):
     if not chord_string or chord_string == 'N': return [], ""
-    
-    # Ignore slash chords for now (e.g., C/E becomes C)
-    chord_string = chord_string.split('/')[0]
-    
+
+    # 1. Check for a slash chord bass note!
+    bass_note_str = None
+    if '/' in chord_string:
+        parts = chord_string.split('/')
+        chord_string = parts[0]     # The main chord (e.g., 'Amin')
+        bass_note_str = parts[1]    # The bass note (e.g., 'E')
+
+    # 2. Parse the main chord's root note
     root_note = chord_string[0]
     remainder = chord_string[1:]
-    
-    # Check for sharps or flats
     if remainder and remainder[0] in ['s', 'b']:
         root_note += remainder[0]
         remainder = remainder[1:]
 
     root_midi = NOTE_TO_MIDI.get(root_note, 60)
     
-    # Default to major if nothing matches
+    # 3. Find the chord quality
     quality = 'maj'
     intervals = CHORD_INTERVALS['maj']
-    
-    # Check against our sorted list (e.g., checks 'min7' before 'min')
     for q in SORTED_QUALITIES:
         if remainder.startswith(q):
             intervals = CHORD_INTERVALS[q]
             quality = q
             break
             
-    return [root_midi + i for i in intervals], quality
+    pitches = [root_midi + i for i in intervals]
+
+    # 4. Inject the custom bass note
+    if bass_note_str:
+        # Parse the bass note (checking for sharps/flats)
+        b_root = bass_note_str[0]
+        b_rem = bass_note_str[1:]
+        if b_rem and b_rem[0] in ['s', 'b']:
+            b_root += b_rem[0]
+
+        bass_midi = NOTE_TO_MIDI.get(b_root, 60)
+
+        # Force the bass note to sit below our root note
+        while bass_midi >= root_midi:
+            bass_midi -= 12
+            
+        # Drop it one more octave for a deep, rich foundation
+        bass_midi -= 12 
+
+        pitches.append(bass_midi)
+        
+        # Update the display name so it shows the slash in the final output!
+        quality += "/" + bass_note_str 
+
+    return pitches, quality
+    
 # General MIDI Patch Numbers (0-indexed)
 INSTRUMENT_MAP = {
     "Acoustic Grand Piano": 0,