Index: music/views.py
===================================================================
--- music/views.py	(revision d4c80c07957ce76ec98052794bc5a3da8d5f08d0)
+++ music/views.py	(revision 04f1bb3b067df3286119ab7f8d90e0a6e3aab1c2)
@@ -284,6 +284,14 @@
 
 def add_tracks_to_playlist(request):
+    search_track = request.GET.get('search_track', '').strip()
+
+    invoices = Invoice.objects.all()
+
+    if search_track:
+        tracks = Track.objects.filter(name__icontains=search_track)
+    else:
+        tracks = Track.objects.all()
+
     playlists = Playlist.objects.all()
-    tracks = Track.objects.all()
     selected_playlist_id = request.POST.get('playlist_id') or request.GET.get('playlist_id')
 
@@ -308,11 +316,19 @@
         'playlists': playlists,
         'tracks': tracks,
-        'selected_playlist_id': selected_playlist_id
+        'selected_playlist_id': selected_playlist_id,
+        'search_track': search_track,
     })
 
 
 def add_invoice_lines_to_invoice(request):
+    search_track = request.GET.get('search_track', '').strip()
+
     invoices = Invoice.objects.all()
-    tracks = Track.objects.all()
+
+    if search_track:
+        tracks = Track.objects.filter(name__icontains=search_track)
+    else:
+        tracks = Track.objects.all()
+
     selected_invoice_id = request.POST.get('invoice_id') or request.GET.get('invoice_id')
 
@@ -344,4 +360,5 @@
         'invoices': invoices,
         'tracks': tracks,
-        'selected_invoice_id': selected_invoice_id
-    })
+        'selected_invoice_id': selected_invoice_id,
+        'search_track': search_track,
+    })
Index: templates/add_invoice_lines_to_invoice.html
===================================================================
--- templates/add_invoice_lines_to_invoice.html	(revision d4c80c07957ce76ec98052794bc5a3da8d5f08d0)
+++ templates/add_invoice_lines_to_invoice.html	(revision 04f1bb3b067df3286119ab7f8d90e0a6e3aab1c2)
@@ -13,4 +13,14 @@
 <div class="container mt-5">
     <h1 class="text-center mb-4">Add Invoice Lines</h1>
+
+    <form method="get" class="mb-3">
+        {% csrf_token %}
+        <input type="hidden" name="invoice_id" value="{{ selected_invoice_id }}">
+        <div class="input-group">
+            <input type="text" name="search_track" class="form-control" placeholder="Search tracks"
+                   value="{{ search_track }}">
+            <button class="btn btn-outline-secondary" type="submit">Search</button>
+        </div>
+    </form>
 
     <form method="post" class="card p-4 shadow-sm bg-white">
@@ -32,6 +42,4 @@
         <div class="row">
             <div class="col-6">
-
-
                 <div class="mb-3">
                     <label class="form-label"><strong>Select Tracks and Quantities</strong></label>
Index: templates/add_tracks_to_playlist.html
===================================================================
--- templates/add_tracks_to_playlist.html	(revision d4c80c07957ce76ec98052794bc5a3da8d5f08d0)
+++ templates/add_tracks_to_playlist.html	(revision 04f1bb3b067df3286119ab7f8d90e0a6e3aab1c2)
@@ -19,4 +19,14 @@
 <div class="container mt-5">
     <h1 class="text-center mb-4">Add Tracks to Playlist</h1>
+
+    <form method="get" class="mb-3">
+        {% csrf_token %}
+        <input type="hidden" name="invoice_id" value="{{ selected_invoice_id }}">
+        <div class="input-group">
+            <input type="text" name="search_track" class="form-control" placeholder="Search tracks"
+                   value="{{ search_track }}">
+            <button class="btn btn-outline-secondary" type="submit">Search</button>
+        </div>
+    </form>
 
     <form method="post" class="card p-4 shadow-sm bg-white">