diff --git a/SDL/font.c b/SDL/font.c
index e3db34e..6cc09a2 100644
--- a/SDL/font.c
+++ b/SDL/font.c
@@ -1129,6 +1129,26 @@ uint8_t font[] = {
     X, _, X, X, _, X,
     X, _, _, _, _, X,
     _, X, X, X, X, _,
+    
+    /* Alt symbol */
+    
+    _, _, X, X, _, _,
+    _, X, _, _, X, _,
+    _, X, _, _, X, _,
+    _, X, _, _, X, _,
+    _, X, X, X, X, _,
+    _, X, _, _, X, _,
+    _, X, _, _, X, _,
+    _, _, _, _, _, _,
+    
+    X, _, _, X, X, X,
+    X, _, _, _, X, _,
+    X, _, _, _, X, _,
+    X, _, _, _, X, _,
+    X, _, _, _, X, _,
+    X, _, _, _, X, _,
+    X, X, X, _, X, _,
+    _, _, _, _, _, _,
 };
 
 const uint8_t font_max = sizeof(font) / GLYPH_HEIGHT / GLYPH_WIDTH + ' ';
diff --git a/SDL/font.h b/SDL/font.h
index a6d331e..ce6044f 100644
--- a/SDL/font.h
+++ b/SDL/font.h
@@ -11,6 +11,7 @@ extern const uint8_t font_max;
 #define SELECTION_STRING RIGHT_ARROW_STRING
 #define CTRL_STRING "\x80\x81\x82"
 #define SHIFT_STRING "\x83"
+#define ALT_STRING "\x91\x92"
 #define CMD_STRING "\x84\x85"
 #define ELLIPSIS_STRING "\x87"
 #define MOJIBAKE_STRING "\x88"
diff --git a/SDL/gui.c b/SDL/gui.c
index b637bd6..0ca5d6d 100644
--- a/SDL/gui.c
+++ b/SDL/gui.c
@@ -76,8 +76,6 @@ void render_texture(void *pixels,  void *previous)
 }
 
 static const char *help[] = {
-"Drop a ROM to play.\n"
-"\n"
 "Keyboard Shortcuts:\n"
 " Open Menu:        Escape\n"
 " Open ROM:          " MODIFIER_NAME "+O\n"
@@ -91,6 +89,7 @@ static const char *help[] = {
 #else
 " Mute/Unmute:       " MODIFIER_NAME "+M\n"
 #endif
+" Toggle channel: " ALT_STRING "+(1-4)\n"
 " Break Debugger:    " CTRL_STRING "+C",
 "\n"
 "SameBoy\n"
diff --git a/SDL/main.c b/SDL/main.c
index c3f9594..48d26c8 100644
--- a/SDL/main.c
+++ b/SDL/main.c
@@ -441,6 +441,16 @@ static void handle_events(GB_gameboy_t *gb)
                                     pending_command = GB_SDL_SAVE_STATE_COMMAND;
                                 }
                             }
+                            else if ((event.key.keysym.mod & KMOD_ALT) && event.key.keysym.scancode <= SDL_SCANCODE_4) {
+                                GB_channel_t channel = event.key.keysym.scancode - SDL_SCANCODE_1;
+                                bool state = !GB_is_channel_muted(gb, channel);
+                                
+                                GB_set_channel_muted(gb, channel, state);
+                                
+                                static char message[18];
+                                sprintf(message, "Channel %d %smuted", channel + 1, state? "" : "un");
+                                show_osd_text(message);
+                            }
                         }
                         break;
                 }