diff --git a/database/migrations/2025_12_18_200239_add_unique_key_to_audition_etudes_table.php b/database/migrations/2025_12_18_200239_add_unique_key_to_audition_etudes_table.php
new file mode 100644
index 0000000..e23b4a3
--- /dev/null
+++ b/database/migrations/2025_12_18_200239_add_unique_key_to_audition_etudes_table.php
@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('audition_etudes', function (Blueprint $table) {
+            $table->unique(['instrument_id', 'auditioned_ensemble_id', 'set']);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('audition_etudes', function (Blueprint $table) {
+            $table->dropUnique(['instrument_id', 'auditioned_ensemble_id', 'set']);
+        });
+    }
+};