Perform octave shifting with correct values

src/main/java/com/cstav/genshinstrument/client/gui/screen/instrument/partial/AbstractInstrumentScreen.java

@@ -555,17 +555,17 @@ protected int handleMidiOverflow(int note) {
                 setPitch(0);
                 ModClientConfigs.PITCH.set(0);
             }
-            // Shift the note to the lower octave
+            // Shift the note to the higher octave
             else
-                note -= minPitch;
+                note += 12;
         }
         else if (getPitch() == maxPitch) {
             if (note < maxMidiNote()) {
                 setPitch(0);
                 ModClientConfigs.PITCH.set(0);
             }
             else
-                note -= maxPitch;
+                note -= 12;
         }
 
         return note;