diff --git a/osu.Game.Rulesets.Karaoke/Beatmaps/Metadatas/SingerInfo.cs b/osu.Game.Rulesets.Karaoke/Beatmaps/Metadatas/SingerInfo.cs
index dd8ea2098..92d772e80 100644
--- a/osu.Game.Rulesets.Karaoke/Beatmaps/Metadatas/SingerInfo.cs
+++ b/osu.Game.Rulesets.Karaoke/Beatmaps/Metadatas/SingerInfo.cs
@@ -14,13 +14,16 @@ public class SingerInfo
     public bool SupportSingerState { get; set; }
 
     // todo: should make the property as readonly.
-    public BindableList<ISinger> Singers { get; set; } = new();
+    public BindableList<Singer> Singers { get; set; } = new();
+
+    // todo: should make the property as readonly.
+    public BindableList<SingerState> SingerState { get; set; } = new();
 
     public IEnumerable<Singer> GetAllSingers() =>
-        Singers.OfType<Singer>().OrderBy(x => x.Order);
+        Singers.OrderBy(x => x.Order);
 
     public IEnumerable<SingerState> GetAllAvailableSingerStates(Singer singer) =>
-        Singers.OfType<SingerState>().Where(x => x.MainSingerId == singer.ID).OrderBy(x => x.Order);
+        SingerState.Where(x => x.MainSingerId == singer.ID).OrderBy(x => x.Order);
 
     public IDictionary<Singer, SingerState[]> GetSingerByIds(ElementId[] singerIds)
     {
@@ -58,7 +61,7 @@ public SingerState AddSingerState(Singer singer, Action<SingerState>? action = n
         var singerState = new SingerState(mainSingerId);
         action?.Invoke(singerState);
 
-        Singers.Add(singerState);
+        SingerState.Add(singerState);
 
         return singerState;
     }
@@ -76,14 +79,24 @@ public bool RemoveSinger(ISinger singer)
                     RemoveSinger(singerState);
                 }
 
-                return Singers.Remove(singer);
+                return Singers.Remove(mainSinger);
             }
 
-            case SingerState:
-                return Singers.Remove(singer);
+            case SingerState singerState:
+                return SingerState.Remove(singerState);
 
             default:
                 throw new InvalidCastException();
         }
     }
+
+    public bool HasSinger(ISinger singer)
+    {
+        return singer switch
+        {
+            Singer mainSinger => Singers.Contains(mainSinger),
+            SingerState singerState => SingerState.Contains(singerState),
+            _ => throw new InvalidCastException(),
+        };
+    }
 }
diff --git a/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/BeatmapSingersChangeHandler.cs b/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/BeatmapSingersChangeHandler.cs
index 691279460..67a5e239c 100644
--- a/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/BeatmapSingersChangeHandler.cs
+++ b/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/BeatmapSingersChangeHandler.cs
@@ -24,7 +24,7 @@ public partial class BeatmapSingersChangeHandler : BeatmapPropertyChangeHandler,
 
     private SingerInfo singerInfo => KaraokeBeatmap.SingerInfo;
 
-    public BindableList<ISinger> Singers => singerInfo.Singers;
+    public BindableList<Singer> Singers => singerInfo.Singers;
 
     public void ChangeOrder(ISinger singer, int newIndex)
     {
@@ -111,7 +111,7 @@ private void performSingerChanged<TSinger>(TSinger singer, Action<TSinger> actio
     {
         performSingerInfoChanged(singerInfo =>
         {
-            if (!singerInfo.Singers.Contains(singer))
+            if (!singerInfo.HasSinger(singer))
                 throw new InvalidOperationException("Singer should be in the beatmap");
 
             action(singer);
diff --git a/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/IBeatmapSingersChangeHandler.cs b/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/IBeatmapSingersChangeHandler.cs
index 9f313238f..299bf5fd0 100644
--- a/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/IBeatmapSingersChangeHandler.cs
+++ b/osu.Game.Rulesets.Karaoke/Edit/ChangeHandlers/Beatmaps/IBeatmapSingersChangeHandler.cs
@@ -11,7 +11,7 @@ namespace osu.Game.Rulesets.Karaoke.Edit.ChangeHandlers.Beatmaps;
 public interface IBeatmapSingersChangeHandler
 {
     // todo: should use IBindableList eventually, but cannot do that because it's bind to selection item.
-    BindableList<ISinger> Singers { get; }
+    BindableList<Singer> Singers { get; }
 
     void ChangeOrder(ISinger singer, int newIndex);
 
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Singers/SingerEditSection.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Singers/SingerEditSection.cs
index 75755c993..cf103cb0d 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Singers/SingerEditSection.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Singers/SingerEditSection.cs
@@ -25,7 +25,7 @@ namespace osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Lyrics.Settings.Singer
 
 public partial class SingerEditSection : LyricPropertySection
 {
-    private readonly IBindableList<ISinger> bindableSingers = new BindableList<ISinger>();
+    private readonly IBindableList<Singer> bindableSingers = new BindableList<Singer>();
     private readonly IBindableList<ElementId> singerIndexes = new BindableList<ElementId>();
     protected override LocalisableString Title => "Singer";
 
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableList.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableList.cs
index f009c7d86..b311b1a32 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableList.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableList.cs
@@ -4,6 +4,7 @@
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Game.Graphics.Containers;
+using osu.Game.Rulesets.Karaoke.Beatmaps.Metadatas;
 using osu.Game.Rulesets.Karaoke.Beatmaps.Metadatas.Types;
 using osu.Game.Rulesets.Karaoke.Graphics.Containers;
 using osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Singers.Rows;
@@ -11,7 +12,7 @@
 
 namespace osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Singers;
 
-public partial class SingerRearrangeableList : OrderRearrangeableListContainer<ISinger>
+public partial class SingerRearrangeableList : OrderRearrangeableListContainer<Singer>
 {
     protected override Vector2 Spacing => new(0, 5);
 
@@ -24,7 +25,7 @@ public SingerRearrangeableList()
         };
     }
 
-    protected override OsuRearrangeableListItem<ISinger> CreateOsuDrawable(ISinger item)
+    protected override OsuRearrangeableListItem<Singer> CreateOsuDrawable(Singer item)
         => new SingerRearrangeableListItem(item);
 
     protected override Drawable CreateBottomDrawable()
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableListItem.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableListItem.cs
index 37ea496df..80e4ae762 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableListItem.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerRearrangeableListItem.cs
@@ -15,20 +15,17 @@
 
 namespace osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Singers;
 
-public partial class SingerRearrangeableListItem : OsuRearrangeableListItem<ISinger>
+public partial class SingerRearrangeableListItem : OsuRearrangeableListItem<Singer>
 {
     private Box dragAlert = null!;
 
-    public SingerRearrangeableListItem(ISinger item)
+    public SingerRearrangeableListItem(Singer item)
         : base(item)
     {
     }
 
     protected override Drawable CreateContent()
     {
-        if (Model is not Singer singer)
-            throw new InvalidCastException($"Currently we are only able to edit the {nameof(Singer)}.");
-
         return new Container
         {
             Masking = true,
@@ -42,7 +39,7 @@ protected override Drawable CreateContent()
                     RelativeSizeAxes = Axes.Both,
                     Alpha = 0,
                 },
-                new SingerLyricPlacementColumn(singer)
+                new SingerLyricPlacementColumn(Model)
                 {
                     RelativeSizeAxes = Axes.Both,
                 },