diff --git a/Content.Server/Instruments/SwappableInstrumentComponent.cs b/Content.Server/Instruments/SwappableInstrumentComponent.cs
index f8b2b97a10..6acf43151d 100644
--- a/Content.Server/Instruments/SwappableInstrumentComponent.cs
+++ b/Content.Server/Instruments/SwappableInstrumentComponent.cs
@@ -11,4 +11,11 @@ public sealed partial class SwappableInstrumentComponent : Component
     /// </summary>
     [DataField("instrumentList", required: true)]
     public Dictionary<string, (byte, byte)> InstrumentList = new();
+
+    // Frontier: harpy instruments
+    /// <summary>
+    /// When true, only the instrument entity itself can swap its sound.
+    /// </summary>
+    [DataField]
+    public bool OnlySetBySelf;
 }
diff --git a/Content.Server/Instruments/SwappableInstrumentSystem.cs b/Content.Server/Instruments/SwappableInstrumentSystem.cs
index 9aef875cd6..81b3b2c100 100644
--- a/Content.Server/Instruments/SwappableInstrumentSystem.cs
+++ b/Content.Server/Instruments/SwappableInstrumentSystem.cs
@@ -25,6 +25,9 @@ public sealed class SwappableInstrumentSystem : EntitySystem
         if (!TryComp<InstrumentComponent>(uid, out var instrument))
             return;
 
+        if (component.OnlySetBySelf && uid != args.User) // Frontier: restrict instrument changes
+            return; // Frontier: restrict instrument changes
+
         var priority = 0;
         foreach (var entry in component.InstrumentList)
         {
diff --git a/Resources/Prototypes/_DV/Entities/Mobs/Species/harpy.yml b/Resources/Prototypes/_DV/Entities/Mobs/Species/harpy.yml
index b6c23584a6..221faf2b77 100644
--- a/Resources/Prototypes/_DV/Entities/Mobs/Species/harpy.yml
+++ b/Resources/Prototypes/_DV/Entities/Mobs/Species/harpy.yml
@@ -22,6 +22,7 @@
       "Piano": {1: 0}
       "Church Organ": {19: 0}
       "Harp": {46: 0}
+    onlySetBySelf: true # Frontier
   - type: UserInterface
     interfaces:
       enum.InstrumentUiKey.Key: