diff --git a/app/app/components/chord-diagram/piano-keys.tsx b/app/app/components/chord-diagram/piano-keys.tsx
index 94aa85c..5b34720 100644
--- a/app/app/components/chord-diagram/piano-keys.tsx
+++ b/app/app/components/chord-diagram/piano-keys.tsx
@@ -7,6 +7,8 @@ const NOTE_CHROMA: Record<string, number> = {
   'G': 7, 'G#': 8, 'Ab': 8,
   'A': 9, 'A#': 10, 'Bb': 10,
   'B': 11, 'Cb': 11, 'B#': 0,
+  // Double-sharps tonal may return (e.g. Baug → F##=G)
+  'C##': 2, 'D##': 4, 'F##': 7, 'G##': 9, 'A##': 11,
 };
 
 const WHITE_KEYS = ['C', 'D', 'E', 'F', 'G', 'A', 'B'];
diff --git a/app/app/lib/guitar-voicings.ts b/app/app/lib/guitar-voicings.ts
index 99b6217..179e664 100644
--- a/app/app/lib/guitar-voicings.ts
+++ b/app/app/lib/guitar-voicings.ts
@@ -18,31 +18,31 @@ export const GUITAR_VOICINGS: Record<string, GuitarVoicingTemplate> = {
   // E major open: [0,2,2,1,0,0]  E B E G# B E
   'major': {
     frets: [0, 2, 2, 1, 0, 0],
-    barre: null,
+    barre: 0,
     rootString: 'E',
   },
   // E7: [0,2,0,1,0,0]  E B D G# B E
   'dominant seventh': {
     frets: [0, 2, 0, 1, 0, 0],
-    barre: null,
+    barre: 0,
     rootString: 'E',
   },
   // Emaj7: [0,2,1,1,0,0]  E B D# G# B E
   'major seventh': {
     frets: [0, 2, 1, 1, 0, 0],
-    barre: null,
+    barre: 0,
     rootString: 'E',
   },
   // Eaug: [0,3,2,1,1,0]  E C(=B#) E G# C E
   'augmented': {
     frets: [0, 3, 2, 1, 1, 0],
-    barre: null,
+    barre: 0,
     rootString: 'E',
   },
   // Esus4: [0,2,2,2,0,0]  E B E A B E
   'suspended fourth': {
     frets: [0, 2, 2, 2, 0, 0],
-    barre: null,
+    barre: 0,
     rootString: 'E',
   },