diff --git a/OpenUtau.Core/Commands/Notifications.cs b/OpenUtau.Core/Commands/Notifications.cs
index 128b468d5..dbdd77b09 100644
--- a/OpenUtau.Core/Commands/Notifications.cs
+++ b/OpenUtau.Core/Commands/Notifications.cs
@@ -26,6 +26,24 @@ public ErrorMessageNotification(string message, Exception e) {
         public override string ToString() => $"Error message: {message} {e}";
     }
 
+    public class LoadingNotification : UNotification {
+        public readonly Type window;
+        public readonly bool startLoading;
+        public readonly string loadObject;
+        public LoadingNotification(Type window, bool startLoading, string loadObject) {
+            this.window = window;
+            this.startLoading = startLoading;
+            this.loadObject = loadObject;
+        }
+        public override string ToString() {
+            if (startLoading) {
+                return $"Start loading {loadObject}";
+            } else {
+                return $"Finish loading {loadObject}";
+            }
+        }
+    }
+
     public class LoadPartNotification : UNotification {
         public readonly int tick;
         public LoadPartNotification(UPart part, UProject project, int tick) {
diff --git a/OpenUtau/ViewModels/MainWindowViewModel.cs b/OpenUtau/ViewModels/MainWindowViewModel.cs
index 07d50d625..4e19271bd 100644
--- a/OpenUtau/ViewModels/MainWindowViewModel.cs
+++ b/OpenUtau/ViewModels/MainWindowViewModel.cs
@@ -5,6 +5,7 @@
 using System.Threading.Tasks;
 using Avalonia.Threading;
 using DynamicData.Binding;
+using OpenUtau.App.Views;
 using OpenUtau.Core;
 using OpenUtau.Core.Ustx;
 using ReactiveUI;
@@ -59,8 +60,7 @@ public MainWindowViewModel() {
                 try {
                     OpenProject(new[] { file });
                 } catch (Exception e) {
-                    DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(
-                        "failed to open recent.", e));
+                    DocManager.Inst.ExecuteCmd(new ErrorMessageNotification("failed to open recent.", e));
                 }
             });
             OpenTemplateCommand = ReactiveCommand.Create<string>(file => {
@@ -69,8 +69,7 @@ public MainWindowViewModel() {
                     DocManager.Inst.Project.Saved = false;
                     DocManager.Inst.Project.FilePath = string.Empty;
                 } catch (Exception e) {
-                    DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(
-                        "failed to open template.", e));
+                    DocManager.Inst.ExecuteCmd(new ErrorMessageNotification("failed to open template.", e));
                 }
             });
             PartDeleteCommand = ReactiveCommand.Create<UPart>(part => {
@@ -109,8 +108,7 @@ public void NewProject() {
                     DocManager.Inst.Project.FilePath = string.Empty;
                     return;
                 } catch (Exception e) {
-                    DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(
-                        "failed to load default template.", e));
+                    DocManager.Inst.ExecuteCmd(new ErrorMessageNotification("failed to load default template.", e));
                 }
             }
             DocManager.Inst.ExecuteCmd(new LoadProjectNotification(Core.Format.Ustx.Create()));
@@ -120,9 +118,14 @@ public void OpenProject(string[] files) {
             if (files == null) {
                 return;
             }
-            Core.Format.Formats.LoadProject(files);
-            DocManager.Inst.ExecuteCmd(new VoiceColorRemappingNotification(-1, true));
-            this.RaisePropertyChanged(nameof(Title));
+            DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(MainWindow), true, "project"));
+            try {
+                Core.Format.Formats.LoadProject(files);
+                DocManager.Inst.ExecuteCmd(new VoiceColorRemappingNotification(-1, true));
+                this.RaisePropertyChanged(nameof(Title));
+            } finally {
+                DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(MainWindow), false, "project"));
+            }
         }
 
         public void SaveProject(string file = "") {
diff --git a/OpenUtau/ViewModels/PianoRollViewModel.cs b/OpenUtau/ViewModels/PianoRollViewModel.cs
index 4993c2102..0456049a7 100644
--- a/OpenUtau/ViewModels/PianoRollViewModel.cs
+++ b/OpenUtau/ViewModels/PianoRollViewModel.cs
@@ -5,6 +5,7 @@
 using Avalonia.Input;
 using Avalonia.Threading;
 using DynamicData.Binding;
+using OpenUtau.App.Views;
 using OpenUtau.Classic;
 using OpenUtau.Core;
 using OpenUtau.Core.Editing;
@@ -120,18 +121,25 @@ public PianoRollViewModel() {
                 if (NotesViewModel.Part == null || NotesViewModel.Part.notes.Count == 0) {
                     return;
                 }
-                var part = NotesViewModel.Part;
-                UNote? first;
-                UNote? last;
-                if (NotesViewModel.Selection.IsEmpty) {
-                    first = part.notes.First();
-                    last = part.notes.Last();
-                } else {
-                    first = NotesViewModel.Selection.FirstOrDefault();
-                    last = NotesViewModel.Selection.LastOrDefault();
+                DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(PianoRollWindow), true, "legacy plugin"));
+                try {
+                    var part = NotesViewModel.Part;
+                    UNote? first;
+                    UNote? last;
+                    if (NotesViewModel.Selection.IsEmpty) {
+                        first = part.notes.First();
+                        last = part.notes.Last();
+                    } else {
+                        first = NotesViewModel.Selection.FirstOrDefault();
+                        last = NotesViewModel.Selection.LastOrDefault();
+                    }
+                    var runner = PluginRunner.from(PathManager.Inst, DocManager.Inst);
+                    runner.Execute(NotesViewModel.Project, part, first, last, plugin);
+                } catch (Exception e) {
+                    DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(e));
+                } finally {
+                    DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(PianoRollWindow), false, "legacy plugin"));
                 }
-                var runner = PluginRunner.from(PathManager.Inst, DocManager.Inst);
-                runner.Execute(NotesViewModel.Project, part, first, last, plugin);
             });
             LoadLegacyPlugins();
 
@@ -139,8 +147,8 @@ public PianoRollViewModel() {
                 if (NotesViewModel.Part != null) {
                     try{
                         edit.Run(NotesViewModel.Project, NotesViewModel.Part, NotesViewModel.Selection.ToList(), DocManager.Inst);
-                    }catch(System.Exception e){
-                        DocManager.Inst.ExecuteCmd(new ErrorMessageNotification("Failed to run editing macro",e));
+                    } catch (Exception e) {
+                        DocManager.Inst.ExecuteCmd(new ErrorMessageNotification("Failed to run editing macro", e));
                     }
                 }
             });
diff --git a/OpenUtau/ViewModels/SingersViewModel.cs b/OpenUtau/ViewModels/SingersViewModel.cs
index 847dd795d..c069e73ae 100644
--- a/OpenUtau/ViewModels/SingersViewModel.cs
+++ b/OpenUtau/ViewModels/SingersViewModel.cs
@@ -10,6 +10,7 @@
 using DynamicData.Binding;
 using NAudio.Wave;
 using NWaves.Signals;
+using OpenUtau.App.Views;
 using OpenUtau.Classic;
 using OpenUtau.Core;
 using OpenUtau.Core.Ustx;
@@ -56,17 +57,36 @@ public SingersViewModel() {
             this.WhenAnyValue(vm => vm.Singer)
                 .WhereNotNull()
                 .Subscribe(singer => {
-                    singer.EnsureLoaded();
-                    Avatar = LoadAvatar(singer);
-                    Otos.Clear();
-                    Otos.AddRange(singer.Otos);
-                    DisplayedOtos.Clear();
-                    DisplayedOtos.AddRange(singer.Otos);
-                    Info = $"Author: {singer.Author}\nVoice: {singer.Voice}\nWeb: {singer.Web}\nVersion: {singer.Version}\n{singer.OtherInfo}\n\n{string.Join("\n", singer.Errors)}";
-                    HasWebsite = !string.IsNullOrEmpty(singer.Web);
-                    LoadSubbanks();
-                    DocManager.Inst.ExecuteCmd(new OtoChangedNotification());
-                    this.RaisePropertyChanged(nameof(IsClassic));
+                    if (MessageBox.LoadingIsActive()) {
+                        try {
+                            AttachSinger();
+                        } catch (Exception e) {
+                            DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(e));
+                        }
+                    } else {
+                        DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(SingersDialog), true, "singer"));
+                        try {
+                            AttachSinger();
+                        } catch (Exception e) {
+                            DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(e));
+                        } finally {
+                            DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(SingersDialog), false, "singer"));
+                        }
+                    }
+                    void AttachSinger() {
+                        singer.EnsureLoaded();
+                        Avatar = LoadAvatar(singer);
+                        Otos.Clear();
+                        Otos.AddRange(singer.Otos);
+                        DisplayedOtos.Clear();
+                        DisplayedOtos.AddRange(singer.Otos);
+                        Info = $"Author: {singer.Author}\nVoice: {singer.Voice}\nWeb: {singer.Web}\nVersion: {singer.Version}\n{singer.OtherInfo}\n\n{string.Join("\n", singer.Errors)}";
+                        HasWebsite = !string.IsNullOrEmpty(singer.Web);
+                        LoadSubbanks();
+                        DocManager.Inst.ExecuteCmd(new OtoChangedNotification());
+                        this.RaisePropertyChanged(nameof(IsClassic));
+                        this.RaisePropertyChanged(nameof(UseSearchAlias));
+                    }
                 });
             this.WhenAnyValue(vm => vm.SearchAlias)
                 .Subscribe(alias => {
@@ -195,15 +215,22 @@ public void Refresh() {
             if (Singer == null) {
                 return;
             }
-            var singerId = Singer.Id;
-            SingerManager.Inst.SearchAllSingers();
-            this.RaisePropertyChanged(nameof(Singers));
-            if (SingerManager.Inst.Singers.TryGetValue(singerId, out var singer)) {
-                Singer = singer;
-            } else {
-                Singer = Singers.FirstOrDefault();
+            DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(SingersDialog), true, "singer"));
+            try {
+                var singerId = Singer.Id;
+                SingerManager.Inst.SearchAllSingers();
+                this.RaisePropertyChanged(nameof(Singers));
+                if (SingerManager.Inst.Singers.TryGetValue(singerId, out var singer)) {
+                    Singer = singer;
+                } else {
+                    Singer = Singers.FirstOrDefault();
+                }
+                DocManager.Inst.ExecuteCmd(new SingersRefreshedNotification());
+            } catch (Exception e) {
+                DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(e));
+            } finally {
+                DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(SingersDialog), false, "singer"));
             }
-            DocManager.Inst.ExecuteCmd(new SingersRefreshedNotification());
         }
 
         Bitmap? LoadAvatar(USinger singer) {
diff --git a/OpenUtau/Views/MainWindow.axaml.cs b/OpenUtau/Views/MainWindow.axaml.cs
index 4c0edc842..f9a843a14 100644
--- a/OpenUtau/Views/MainWindow.axaml.cs
+++ b/OpenUtau/Views/MainWindow.axaml.cs
@@ -16,6 +16,7 @@
 using OpenUtau.App.ViewModels;
 using OpenUtau.Classic;
 using OpenUtau.Core;
+using OpenUtau.Core.DiffSinger;
 using OpenUtau.Core.Format;
 using OpenUtau.Core.Ustx;
 using OpenUtau.Core.Util;
@@ -23,8 +24,6 @@
 using Serilog;
 using Point = Avalonia.Point;
 
-using OpenUtau.Core.DiffSinger;
-
 namespace OpenUtau.App.Views {
     public partial class MainWindow : Window, ICmdSubscriber {
         private readonly KeyModifiers cmdKey =
@@ -475,25 +474,33 @@ public void OpenSingersWindow() {
             if (lifetime == null) {
                 return;
             }
-            var dialog = lifetime.Windows.FirstOrDefault(w => w is SingersDialog);
-            if (dialog == null) {
-                USinger? singer = null;
-                if (viewModel.TracksViewModel.SelectedParts.Count > 0) {
-                    singer = viewModel.TracksViewModel.Tracks[viewModel.TracksViewModel.SelectedParts.First().trackNo].Singer;
-                }
-                if (singer == null && viewModel.TracksViewModel.Tracks.Count > 0) {
-                    singer = viewModel.TracksViewModel.Tracks.First().Singer;
+
+            DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(MainWindow), true, "singers window"));
+            try {
+                var dialog = lifetime.Windows.FirstOrDefault(w => w is SingersDialog);
+                if (dialog == null) {
+                    USinger? singer = null;
+                    if (viewModel.TracksViewModel.SelectedParts.Count > 0) {
+                        singer = viewModel.TracksViewModel.Tracks[viewModel.TracksViewModel.SelectedParts.First().trackNo].Singer;
+                    }
+                    if (singer == null && viewModel.TracksViewModel.Tracks.Count > 0) {
+                        singer = viewModel.TracksViewModel.Tracks.First().Singer;
+                    }
+                    var vm = new SingersViewModel();
+                    if (singer != null) {
+                        vm.Singer = singer;
+                    }
+                    dialog = new SingersDialog() { DataContext = vm };
+                    dialog.Show();
                 }
-                var vm = new SingersViewModel();
-                if (singer != null) {
-                    vm.Singer = singer;
+                dialog.Activate();
+                if (dialog.Position.Y < 0) {
+                    dialog.Position = dialog.Position.WithY(0);
                 }
-                dialog = new SingersDialog() { DataContext = vm };
-                dialog.Show();
-            }
-            dialog.Activate();
-            if (dialog.Position.Y < 0) {
-                dialog.Position = dialog.Position.WithY(0);
+            } catch (Exception e) {
+                DocManager.Inst.ExecuteCmd(new ErrorMessageNotification(e));
+            } finally {
+                DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(MainWindow), false, "singers window"));
             }
         }
 
@@ -973,10 +980,12 @@ public void PartsCanvasDoubleTapped(object sender, TappedEventArgs args) {
             var control = canvas.InputHitTest(args.GetPosition(canvas));
             if (control is PartControl partControl && partControl.part is UVoicePart) {
                 if (pianoRollWindow == null) {
+                    DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(MainWindow), true, "pianoroll window"));
                     pianoRollWindow = new PianoRollWindow() {
                         MainWindow = this,
                     };
                     pianoRollWindow.ViewModel.PlaybackViewModel = viewModel.PlaybackViewModel;
+                    DocManager.Inst.ExecuteCmd(new LoadingNotification(typeof(MainWindow), false, "pianoroll window"));
                 }
                 // Workaround for new window losing focus.
                 openPianoRollWindow = true;
@@ -1161,6 +1170,12 @@ private async Task<bool> AskIfSaveAndContinue() {
         public void OnNext(UCommand cmd, bool isUndo) {
             if (cmd is ErrorMessageNotification notif) {
                 MessageBox.ShowError(this, notif.message, notif.e);
+            } else if (cmd is LoadingNotification loadingNotif && loadingNotif.window == typeof(MainWindow)) {
+                if (loadingNotif.startLoading) {
+                    MessageBox.ShowLoading(this);
+                } else {
+                    MessageBox.CloseLoading();
+                }
             } else if (cmd is VoiceColorRemappingNotification voicecolorNotif) {
                 if(voicecolorNotif.TrackNo < 0 || DocManager.Inst.Project.tracks.Count <= voicecolorNotif.TrackNo) {
                     ValidateTracksVoiceColor();
diff --git a/OpenUtau/Views/MessageBox.axaml.cs b/OpenUtau/Views/MessageBox.axaml.cs
index 1fd29eceb..ee5f8f21b 100644
--- a/OpenUtau/Views/MessageBox.axaml.cs
+++ b/OpenUtau/Views/MessageBox.axaml.cs
@@ -10,6 +10,8 @@ public partial class MessageBox : Window {
         public enum MessageBoxButtons { Ok, OkCancel, YesNo, YesNoCancel, OkCopy }
         public enum MessageBoxResult { Ok, Cancel, Yes, No }
 
+        private static MessageBox? loadingDialog;
+
         public MessageBox() {
             InitializeComponent();
         }
@@ -102,5 +104,23 @@ public static MessageBox ShowModal(Window parent, string text, string title) {
             msgbox.ShowDialog(parent);
             return msgbox;
         }
+
+        public static void ShowLoading(Window parent) {
+            loadingDialog = new MessageBox() {
+                Title = "Loading"
+            };
+            loadingDialog.Text.Text = "Please wait...";
+            loadingDialog.Show(parent);
+        }
+
+        public static void CloseLoading() {
+            if (loadingDialog != null) {
+                loadingDialog.Close();
+            }
+        }
+
+        public static bool LoadingIsActive() {
+            return loadingDialog != null && loadingDialog.IsActive;
+        }
     }
 }
diff --git a/OpenUtau/Views/PianoRollWindow.axaml.cs b/OpenUtau/Views/PianoRollWindow.axaml.cs
index e60133ed6..3448cc665 100644
--- a/OpenUtau/Views/PianoRollWindow.axaml.cs
+++ b/OpenUtau/Views/PianoRollWindow.axaml.cs
@@ -21,7 +21,7 @@ interface IValueTip {
         void UpdateValueTip(string text);
     }
 
-    public partial class PianoRollWindow : Window, IValueTip {
+    public partial class PianoRollWindow : Window, IValueTip, ICmdSubscriber {
         public MainWindow? MainWindow { get; set; }
         public readonly PianoRollViewModel ViewModel;
 
@@ -58,6 +58,8 @@ public PianoRollWindow() {
             noteDefaultsCommand = ReactiveCommand.Create(() => {
                 EditNoteDefaults();
             });
+
+            DocManager.Inst.AddSubscriber(this);
         }
 
         public void WindowDeactivated(object sender, EventArgs args) {
@@ -1376,5 +1378,15 @@ public void AttachExpressions() {
             exps[DocManager.Inst.Project.expSecondary].SelectExp();
             exps[DocManager.Inst.Project.expPrimary].SelectExp();
         }
+
+        public void OnNext(UCommand cmd, bool isUndo) {
+            if (cmd is LoadingNotification loadingNotif && loadingNotif.window == typeof(PianoRollWindow)) {
+                if (loadingNotif.startLoading) {
+                    MessageBox.ShowLoading(this);
+                } else {
+                    MessageBox.CloseLoading();
+                }
+            }
+        }
     }
 }
diff --git a/OpenUtau/Views/SingersDialog.axaml.cs b/OpenUtau/Views/SingersDialog.axaml.cs
index f52a78362..900630ba0 100644
--- a/OpenUtau/Views/SingersDialog.axaml.cs
+++ b/OpenUtau/Views/SingersDialog.axaml.cs
@@ -421,7 +421,13 @@ void OnKeyDown(object sender, KeyEventArgs args) {
         #region ICmdSubscriber
 
         public void OnNext(UCommand cmd, bool isUndo) {
-            if (cmd is OtoChangedNotification otoChanged) {
+            if (cmd is LoadingNotification loadingNotif && loadingNotif.window == typeof(SingersDialog)) {
+                if (loadingNotif.startLoading) {
+                    MessageBox.ShowLoading(this);
+                } else {
+                    MessageBox.CloseLoading();
+                }
+            } else if (cmd is OtoChangedNotification otoChanged) {
                 var viewModel = DataContext as SingersViewModel;
                 if (viewModel == null) {
                     return;