diff --git a/example/Main.gd b/example/Main.gd
index 0530169..43d3128 100644
--- a/example/Main.gd
+++ b/example/Main.gd
@@ -15,6 +15,7 @@ extends Control
 @onready var _piano_view: Control = %PianoView
 @onready var _tunes_view: Control = %TunesView
 
+@onready var _volume_slider: HSlider = %VolumeSlider
 @onready var _kenney_label := %KenneyLabel
 
 var _current_view: Controller.AppView = Controller.AppView.WELCOME_VIEW
@@ -23,9 +24,11 @@ var _current_view: Controller.AppView = Controller.AppView.WELCOME_VIEW
 func _ready() -> void:
 	get_window().min_size = Vector2(640, 360)
 	_update_active_view(Controller.AppView.WELCOME_VIEW, true)
+	Controller.music_player.change_volume(int(_volume_slider.value))
 
 	_piano_view_button.pressed.connect(Controller.change_app_view.bind(Controller.AppView.PIANO_VIEW))
 	_tunes_view_button.pressed.connect(Controller.change_app_view.bind(Controller.AppView.TUNES_VIEW))
+	_volume_slider.value_changed.connect(Controller.music_player.change_volume)
 	_kenney_label.meta_clicked.connect(_handle_meta_clicked)
 
 	Controller.app_view_changed.connect(_update_active_view.bind(false))
diff --git a/example/Main.tscn b/example/Main.tscn
index f00ea14..164905b 100644
--- a/example/Main.tscn
+++ b/example/Main.tscn
@@ -1,4 +1,4 @@
-[gd_scene load_steps=9 format=3 uid="uid://btlcavlirkxet"]
+[gd_scene load_steps=10 format=3 uid="uid://btlcavlirkxet"]
 
 [ext_resource type="Script" path="res://Main.gd" id="1_8sk4m"]
 [ext_resource type="PackedScene" uid="uid://dp02gpc8hg7fw" path="res://gui/components/FlatButton.tscn" id="2_7ss6h"]
@@ -8,6 +8,7 @@
 [ext_resource type="Texture2D" uid="uid://5pxu35ux4hkn" path="res://icons/piano.png" id="3_cw50e"]
 [ext_resource type="PackedScene" uid="uid://cwl0nh1ofpudo" path="res://gui/TunesView.tscn" id="3_k0wkn"]
 [ext_resource type="Texture2D" uid="uid://ceui0jym6bois" path="res://icons/note.png" id="4_s2pjj"]
+[ext_resource type="Texture2D" uid="uid://cunfeny5nkxdn" path="res://icons/volume.png" id="9_te82j"]
 
 [node name="Main" type="Control"]
 layout_mode = 3
@@ -28,7 +29,7 @@ grow_vertical = 2
 theme_override_constants/margin_left = 12
 theme_override_constants/margin_top = 110
 theme_override_constants/margin_right = 12
-theme_override_constants/margin_bottom = 36
+theme_override_constants/margin_bottom = 48
 
 [node name="WelcomeView" parent="Views" instance=ExtResource("2_d1bku")]
 unique_name_in_owner = true
@@ -62,12 +63,12 @@ text = "GDSiON"
 
 [node name="ViewSelectorFiller" type="Control" parent="TopBar"]
 unique_name_in_owner = true
-visible = false
 layout_mode = 2
 size_flags_horizontal = 3
 
 [node name="ViewSelector" type="HBoxContainer" parent="TopBar"]
 unique_name_in_owner = true
+visible = false
 layout_mode = 2
 size_flags_horizontal = 3
 alignment = 1
@@ -94,6 +95,31 @@ texture = ExtResource("3_7khnb")
 expand_mode = 1
 stretch_mode = 5
 
+[node name="Volume" type="HBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 2
+anchor_top = 1.0
+anchor_bottom = 1.0
+offset_left = 10.0
+offset_top = -40.0
+offset_right = 246.0
+offset_bottom = -8.0
+grow_vertical = 0
+
+[node name="VolumeIcon" type="TextureRect" parent="Volume"]
+custom_minimum_size = Vector2(32, 32)
+layout_mode = 2
+texture = ExtResource("9_te82j")
+expand_mode = 1
+stretch_mode = 5
+
+[node name="VolumeSlider" type="HSlider" parent="Volume"]
+unique_name_in_owner = true
+custom_minimum_size = Vector2(200, 0)
+layout_mode = 2
+size_flags_vertical = 1
+value = 75.0
+
 [node name="KenneyLabel" type="RichTextLabel" parent="."]
 unique_name_in_owner = true
 layout_mode = 1
@@ -104,7 +130,7 @@ anchor_right = 1.0
 anchor_bottom = 1.0
 offset_left = -249.0
 offset_top = -27.0
-offset_right = -2.0
+offset_right = -7.0
 offset_bottom = -7.0
 grow_horizontal = 0
 grow_vertical = 0
diff --git a/example/globals/MusicPlayer.gd b/example/globals/MusicPlayer.gd
index 99f05a5..edf0659 100644
--- a/example/globals/MusicPlayer.gd
+++ b/example/globals/MusicPlayer.gd
@@ -169,6 +169,12 @@ func change_filter_power(value: int) -> void:
 	filter_changed.emit()
 
 
+func change_volume(value: int) -> void:
+	var volume := clampi(value, 0, 100)
+
+	_driver.volume = (volume / 100.0)
+
+
 # Output and streaming control.
 
 func stop() -> void:
diff --git a/example/gui/TunesView.gd b/example/gui/TunesView.gd
index 09219e0..ee1d4e5 100644
--- a/example/gui/TunesView.gd
+++ b/example/gui/TunesView.gd
@@ -32,6 +32,7 @@ func _ready() -> void:
 func _set_view_active() -> void:
 	if not visible:
 		_tune_status.text = ""
+		_tune_status.tooltip_text = ""
 		return
 
 
@@ -48,11 +49,13 @@ func _play_selected() -> void:
 		_tune_status.text = "Now Playing: %s" % [ selected_tune.title ]
 	else:
 		_tune_status.text = "Now Playing: %s by %s" % [ selected_tune.title, selected_tune.author ]
+	_tune_status.tooltip_text = _tune_status.text
 
 
 func _stop_playback() -> void:
 	Controller.music_player.stop()
 	_tune_status.text = ""
+	_tune_status.tooltip_text = ""
 
 
 # Tune management.
diff --git a/example/gui/TunesView.tscn b/example/gui/TunesView.tscn
index db060fc..1ca9600 100644
--- a/example/gui/TunesView.tscn
+++ b/example/gui/TunesView.tscn
@@ -31,8 +31,8 @@ theme_override_constants/separation = 16
 
 [node name="Controls" type="HBoxContainer" parent="Layout/Playback"]
 layout_mode = 2
-size_flags_horizontal = 8
 theme_override_constants/separation = 12
+alignment = 2
 
 [node name="PlayButton" parent="Layout/Playback/Controls" instance=ExtResource("2_c6y1p")]
 unique_name_in_owner = true
@@ -59,7 +59,9 @@ size_flags_vertical = 3
 [node name="TuneStatus" type="Label" parent="Layout/Playback"]
 unique_name_in_owner = true
 layout_mode = 2
+mouse_filter = 1
 theme_override_font_sizes/font_size = 24
+text_overrun_behavior = 1
 
 [node name="HTTPRequest" type="HTTPRequest" parent="."]
 unique_name_in_owner = true
diff --git a/example/icons/volume.png b/example/icons/volume.png
new file mode 100644
index 0000000..3250a72
Binary files /dev/null and b/example/icons/volume.png differ
diff --git a/example/icons/volume.png.import b/example/icons/volume.png.import
new file mode 100644
index 0000000..5c0c484
--- /dev/null
+++ b/example/icons/volume.png.import
@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://cunfeny5nkxdn"
+path="res://.godot/imported/volume.png-4aaf602240d33d2298951d35d959a50c.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://icons/volume.png"
+dest_files=["res://.godot/imported/volume.png-4aaf602240d33d2298951d35d959a50c.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
diff --git a/example/project_theme.tres b/example/project_theme.tres
index a310b9b..d5de3c6 100644
--- a/example/project_theme.tres
+++ b/example/project_theme.tres
@@ -1,4 +1,4 @@
-[gd_resource type="Theme" load_steps=7 format=3 uid="uid://bm402itx0nq0t"]
+[gd_resource type="Theme" load_steps=8 format=3 uid="uid://bm402itx0nq0t"]
 
 [ext_resource type="FontFile" uid="uid://c4b0xfmxt4on2" path="res://fonts/NotoSans-SemiBold.ttf" id="1_2oopj"]
 [ext_resource type="FontFile" uid="uid://y70lqerdtol1" path="res://fonts/Kenney Future Narrow.ttf" id="1_8d45h"]
@@ -27,6 +27,22 @@ corner_radius_top_right = 4
 corner_radius_bottom_right = 4
 corner_radius_bottom_left = 4
 
+[sub_resource type="StyleBoxFlat" id="StyleBoxFlat_wqqdn"]
+content_margin_left = 12.0
+content_margin_top = 8.0
+content_margin_right = 12.0
+content_margin_bottom = 8.0
+bg_color = Color(0.123694, 0.138055, 0.166794, 1)
+border_width_left = 1
+border_width_top = 1
+border_width_right = 1
+border_width_bottom = 1
+border_color = Color(0.0343809, 0.0400633, 0.0557284, 1)
+corner_radius_top_left = 2
+corner_radius_top_right = 2
+corner_radius_bottom_right = 2
+corner_radius_bottom_left = 2
+
 [resource]
 default_font = ExtResource("1_8d45h")
 default_font_size = 30
@@ -50,5 +66,6 @@ ItemList/styles/panel = SubResource("StyleBoxFlat_h73hr")
 ItemList/styles/selected = SubResource("StyleBoxFlat_6uu3r")
 TooltipLabel/font_sizes/font_size = 20
 TooltipLabel/fonts/font = ExtResource("1_2oopj")
+TooltipPanel/styles/panel = SubResource("StyleBoxFlat_wqqdn")
 WelcomeLabel/base_type = &"Label"
 WelcomeLabel/fonts/font = ExtResource("1_2oopj")
diff --git a/src/sequencer/simml_sequencer.cpp b/src/sequencer/simml_sequencer.cpp
index 2687339..b34face 100644
--- a/src/sequencer/simml_sequencer.cpp
+++ b/src/sequencer/simml_sequencer.cpp
@@ -472,23 +472,15 @@ void SiMMLSequencer::process() {
 
 // Parser.
 
-String SiMMLSequencer::_expand_macro(String p_macro, bool p_nested) {
+String SiMMLSequencer::_expand_macro(String p_macro, uint32_t p_macro_flags) {
 	// Note that the original code has a broken circular call check. It never updates the flag
 	// storage, and the check is written incorrectly too. We attempt to fix it here based on the
 	// intention of the original code rather than the actual implementation.
 
-	static uint32_t flag_macro_expanded = 0;
-
 	if (p_macro.is_empty()) {
 		return "";
 	}
 
-	if (!p_nested) {
-		// This is a top-level call, so we reset the flag storage.
-		// We expect only one chain of _expand_macro() calls to be executed at the same time.
-		flag_macro_expanded = 0;
-	}
-
 	String expanded_macro = p_macro;
 
 	Ref<RegEx> re_macro = RegEx::create_from_string("([A-Z])(\\(([\\-\\d]+)\\))?");
@@ -496,27 +488,33 @@ String SiMMLSequencer::_expand_macro(String p_macro, bool p_nested) {
 	// Iterate backwards so we can do in-place replacements without disturbing indices.
 	for (int i = matches.size() - 1; i >= 0; i--) {
 		Ref<RegExMatch> res = matches[i];
-
 		int index = res->get_string(1).unicode_at(0) - 'A';
 
 		// Check for circular calls.
+
+		// The set of flags is unique to each chain of nested calls, which is how we detect circular
+		// calls without getting false positives on sibling macros (e.g. "AAA").
+		uint32_t expanded_macro_flags = p_macro_flags;
+
 		int flag = 1 << index;
-		ERR_FAIL_COND_V_MSG(flag_macro_expanded & flag, p_macro, vformat("SiMMLSequencer: Failed to expand a macro due to a circular reference, '%s'.", res->get_string()));
-		flag_macro_expanded |= flag;
+		ERR_FAIL_COND_V_MSG(expanded_macro_flags & flag, p_macro, vformat("SiMMLSequencer: Failed to expand a macro due to a circular reference, '%s'.", res->get_string()));
+		expanded_macro_flags |= flag;
+
+		// Find the replacement string.
 
 		String replacement;
 		if (!_macro_strings[index].is_empty()) {
 			const String macro_string = _macro_strings[index];
+			replacement = (_macro_expand_dynamic ? _expand_macro(macro_string, expanded_macro_flags) : macro_string);
 
+			// Apply a note shift to the expanded macro.
 			if (!res->get_string(2).is_empty()) {
-				int t = 0;
+				int note_shift = 0;
 				if (!res->get_string(3).is_empty()) {
-					t = res->get_string(3).to_int();
+					note_shift = res->get_string(3).to_int();
 				}
 
-				replacement = "!@ns" + itos(t) + (_macro_expand_dynamic ? _expand_macro(macro_string, true) : macro_string) + "!@ns" + itos(-t);
-			} else {
-				replacement = (_macro_expand_dynamic ? _expand_macro(macro_string, true) : macro_string);
+				replacement = "!@ns" + itos(note_shift) + replacement + "!@ns" + itos(-note_shift);
 			}
 		}
 
diff --git a/src/sequencer/simml_sequencer.h b/src/sequencer/simml_sequencer.h
index e0c83f0..b1e3cbd 100644
--- a/src/sequencer/simml_sequencer.h
+++ b/src/sequencer/simml_sequencer.h
@@ -67,7 +67,7 @@ class SiMMLSequencer : public MMLSequencer {
 	Vector<String> _macro_strings;
 	bool _macro_expand_dynamic = false;
 
-	String _expand_macro(String p_macro, bool p_nested = false);
+	String _expand_macro(String p_macro, uint32_t p_macro_flags = 0);
 
 	int _internal_table_index = 0;