diff --git a/make_post_sell/lib/karaoke.py b/make_post_sell/lib/karaoke.py
new file mode 100644
index 0000000..1aaff33
--- /dev/null
+++ b/make_post_sell/lib/karaoke.py
@@ -0,0 +1,292 @@
+"""Karaoke mode — vocal isolation via unsandbox zerotrust containers.
+
+Downloads media from S3, sends it + voxsplit.c into a zerotrust container
+(no network, destroyed after use), gets back both instrumentals and vocals,
+uploads them to S3.
+
+Uses the unsandbox Python SDK (~/git/un-inception/un.py) for API auth.
+"""
+
+import base64
+import logging
+import os
+import sys
+import tempfile
+import threading
+from concurrent.futures import ThreadPoolExecutor, as_completed
+
+log = logging.getLogger(__name__)
+
+# Use the unsandbox Python SDK for API requests
+sys.path.insert(0, os.path.expanduser("~/git/un-inception"))
+from un import _make_request, _resolve_credentials  # noqa: E402
+
+VOXSPLIT_SOURCE = os.environ.get(
+    "VOXSPLIT_SOURCE_PATH",
+    os.path.expanduser("~/git/uncloseai-cli/audiotoys/voxsplit.c"),
+)
+
+
+def process_karaoke(s3_client, bucket, s3_key, s3_path,
+                    is_video, extension, public_key=None, secret_key=None):
+    """Download from S3 -> process in unsandbox zerotrust -> upload both tracks.
+
+    Produces two files under s3_path:
+        {s3_path}/instrumentals
+        {s3_path}/vocals
+
+    Returns dict {"instrumentals": size, "vocals": size} on success, None on failure.
+    """
+    public_key, secret_key = _resolve_credentials(public_key, secret_key)
+
+    with tempfile.TemporaryDirectory(prefix="karaoke_") as tmpdir:
+        # 1. Download original from S3
+        local_path = os.path.join(tmpdir, "media")
+        s3_client.download_file(bucket, s3_key, local_path)
+
+        # 2. Read and base64 encode
+        with open(local_path, "rb") as f:
+            media_b64 = base64.b64encode(f.read()).decode()
+        with open(VOXSPLIT_SOURCE, "r") as f:
+            voxsplit_src = f.read()
+        voxsplit_b64 = base64.b64encode(voxsplit_src.encode()).decode()
+
+        # 3. Build execution script — produce both tracks
+        if is_video:
+            inst_name = f"instrumentals.{extension}"
+            vocals_name = f"vocals.{extension}"
+            script = (
+                "gcc -O2 -o /tmp/voxsplit /tmp/input/voxsplit.c -lm && "
+                "/tmp/voxsplit /tmp/input/media -o /tmp/split && "
+                "mkdir -p /tmp/artifacts && "
+                f"ffmpeg -y -i /tmp/input/media -i /tmp/split-instrumental.wav "
+                f"-c:v copy -map 0:v -map 1:a -shortest /tmp/artifacts/{inst_name} && "
+                f"ffmpeg -y -i /tmp/input/media -i /tmp/split-vocal.wav "
+                f"-c:v copy -map 0:v -map 1:a -shortest /tmp/artifacts/{vocals_name}"
+            )
+        else:
+            inst_name = "instrumentals.wav"
+            vocals_name = "vocals.wav"
+            script = (
+                "gcc -O2 -o /tmp/voxsplit /tmp/input/voxsplit.c -lm && "
+                "/tmp/voxsplit /tmp/input/media -o /tmp/split && "
+                "mkdir -p /tmp/artifacts && "
+                "cp /tmp/split-instrumental.wav /tmp/artifacts/instrumentals.wav && "
+                "cp /tmp/split-vocal.wav /tmp/artifacts/vocals.wav"
+            )
+
+        # 4. Call unsandbox execute API via SDK
+        payload = {
+            "language": "bash",
+            "code": script,
+            "network_mode": "zerotrust",
+            "ttl": 300,
+            "vcpu": 2,
+            "input_files": [
+                {"filename": "media", "content": media_b64},
+                {"filename": "voxsplit.c", "content": voxsplit_b64},
+            ],
+        }
+
+        try:
+            result = _make_request("POST", "/execute", public_key, secret_key, payload)
+        except Exception:
+            return None
+
+        if not result.get("success") or result.get("exit_code") != 0:
+            return None
+
+        # 5. Extract artifacts and upload to S3
+        artifacts = result.get("artifacts", [])
+        if len(artifacts) < 2:
+            return None
+
+        # Map artifact filenames to track names
+        artifact_map = {}
+        for a in artifacts:
+            fname = a.get("filename", "")
+            if fname.startswith("instrumentals"):
+                artifact_map["instrumentals"] = a
+            elif fname.startswith("vocals"):
+                artifact_map["vocals"] = a
+
+        if "instrumentals" not in artifact_map or "vocals" not in artifact_map:
+            return None
+
+        sizes = {}
+        content_type = "video/mp4" if is_video else "audio/wav"
+
+        for track_name in ("instrumentals", "vocals"):
+            artifact = artifact_map[track_name]
+            data = base64.b64decode(artifact["content_base64"])
+            local_file = os.path.join(tmpdir, track_name)
+            with open(local_file, "wb") as f:
+                f.write(data)
+
+            s3_client.upload_file(
+                local_file, bucket, f"{s3_path}/{track_name}",
+                ExtraArgs={
+                    "CacheControl": "private, max-age=172800",
+                    "ContentType": content_type,
+                },
+            )
+            sizes[track_name] = len(data)
+
+        return sizes
+
+
+def tracks_exist(s3_client, bucket, s3_path):
+    """Check if instrumentals and vocals already exist in S3."""
+    for track in ("instrumentals", "vocals"):
+        try:
+            s3_client.head_object(Bucket=bucket, Key=f"{s3_path}/{track}")
+        except Exception:
+            return False
+    return True
+
+
+# Background backfill guard — one per shop, same pattern as reforge_discovery_ring_async
+_backfill_lock = threading.Lock()
+_backfill_running = set()
+
+
+def backfill_karaoke_async(shop_id, session_factory, app_settings):
+    """Backfill vocal isolation tracks for a shop's catalog using a thread pool.
+
+    Pool size matches the unsandbox account's concurrency limit (from validate_keys).
+    """
+    shop_id_str = str(shop_id)
+
+    with _backfill_lock:
+        if shop_id_str in _backfill_running:
+            return  # already running for this shop
+        _backfill_running.add(shop_id_str)
+
+    def _backfill():
+        try:
+            import boto3
+            from sqlalchemy.orm import Session as SASession
+            from ..models.product import Product, get_media_type
+            from ..models.shop import Shop
+            from un import validate_keys
+
+            session = SASession(bind=session_factory().get_bind())
+
+            def _make_s3():
+                return boto3.session.Session().client(
+                    "s3",
+                    region_name=app_settings["bucket.secure_uploads.region"],
+                    endpoint_url=app_settings["bucket.secure_uploads.post_endpoint"],
+                    aws_access_key_id=app_settings["bucket.secure_uploads.access_key"],
+                    aws_secret_access_key=app_settings["bucket.secure_uploads.secret_key"],
+                )
+
+            s3 = _make_s3()
+            bucket = app_settings["bucket.secure_uploads"]
+
+            try:
+                shop = session.get(Shop, shop_id)
+                if not shop or not shop.unsandbox_public_key or not shop.unsandbox_secret_key:
+                    return
+
+                pk, sk = shop.unsandbox_public_key, shop.unsandbox_secret_key
+
+                # Query account concurrency from unsandbox API
+                try:
+                    key_info = validate_keys(pk, sk)
+                    concurrency = int(key_info.get("concurrency", 1))
+                except Exception:
+                    concurrency = 1
+                concurrency = max(1, concurrency)
+                log.info("Backfill karaoke for shop %s — %d concurrent workers", shop.name, concurrency)
+
+                # Collect work items
+                work = []
+                products = session.query(Product).filter(Product.shop_id == shop_id).all()
+                for product in products:
+                    for file_key in ("product", "preview"):
+                        ext = product.extensions.get(file_key)
+                        if not ext:
+                            continue
+                        media_type = get_media_type(ext)
+                        if media_type not in ("video", "audio"):
+                            continue
+                        if tracks_exist(s3, bucket, product.s3_path):
+                            continue
+                        work.append((product.id, product.s3_path, product.title, file_key, ext, media_type))
+
+                if not work:
+                    log.info("No products need backfill for shop %s", shop.name)
+                    return
+
+                MAX_RETRIES = 3
+                BACKOFF_BASE = 5  # seconds
+
+                # Process a single product with retries (runs in pool thread)
+                def _process_one(item):
+                    product_id, s3_path, title, file_key, ext, media_type = item
+                    thread_s3 = _make_s3()
+                    is_video = (media_type == "video")
+
+                    for attempt in range(MAX_RETRIES):
+                        log.info("Backfill karaoke: %s (%s) attempt %d/%d",
+                                 title, file_key, attempt + 1, MAX_RETRIES)
+                        try:
+                            sizes = process_karaoke(
+                                thread_s3, bucket,
+                                f"{s3_path}/{file_key}",
+                                s3_path, is_video, ext,
+                                public_key=pk, secret_key=sk,
+                            )
+                            if sizes:
+                                return product_id, title, file_key, ext, media_type, sizes
+                        except Exception:
+                            log.exception("Backfill attempt %d failed for %s", attempt + 1, title)
+
+                        if attempt < MAX_RETRIES - 1:
+                            import time as _time
+                            wait = BACKOFF_BASE * (2 ** attempt)
+                            log.info("  Retrying %s in %ds...", title, wait)
+                            _time.sleep(wait)
+
+                    return product_id, title, file_key, ext, media_type, None
+
+                # Fan out with thread pool
+                with ThreadPoolExecutor(max_workers=concurrency) as pool:
+                    futures = {pool.submit(_process_one, item): item for item in work}
+                    for future in as_completed(futures):
+                        try:
+                            product_id, title, file_key, ext, media_type, sizes = future.result()
+                        except Exception:
+                            item = futures[future]
+                            log.exception("Backfill worker crashed for %s", item[2])
+                            continue
+
+                        if sizes:
+                            # DB write only on success — no partial state
+                            product = session.get(Product, product_id)
+                            if not product:
+                                continue
+                            track_ext = ext if media_type == "video" else "wav"
+                            for track_name in ("instrumentals", "vocals"):
+                                product.set_file_metadata(track_name, track_ext, f"{track_name}.{track_ext}")
+                            tmp = product.file_bytes
+                            tmp.update(sizes)
+                            product.file_bytes = tmp
+                            session.add(product)
+                            session.commit()
+                            log.info("  OK %s (inst=%dB, vox=%dB)", title, sizes["instrumentals"], sizes["vocals"])
+                        else:
+                            log.warning("  FAILED %s after %d attempts", title, MAX_RETRIES)
+
+            except Exception:
+                session.rollback()
+                log.exception("Background karaoke backfill failed for shop %s", shop_id_str)
+            finally:
+                session.close()
+        finally:
+            with _backfill_lock:
+                _backfill_running.discard(shop_id_str)
+
+    t = threading.Thread(target=_backfill, daemon=True)
+    t.start()
diff --git a/make_post_sell/models/product.py b/make_post_sell/models/product.py
index bdc33da..d6caba3 100644
--- a/make_post_sell/models/product.py
+++ b/make_post_sell/models/product.py
@@ -168,6 +168,8 @@ class Product(RBase, Base):
         "thumbnail2",
         "thumbnail3",
         "thumbnail4",
+        "instrumentals",
+        "vocals",
     ]
 
     file_public_keys = [
diff --git a/make_post_sell/models/shop.py b/make_post_sell/models/shop.py
index a8dace6..0fa643a 100644
--- a/make_post_sell/models/shop.py
+++ b/make_post_sell/models/shop.py
@@ -100,6 +100,10 @@ class Shop(RBase, Base):
     adyen_hmac_key = Column(Unicode(128), nullable=True)
     adyen_enabled = Column(Boolean, default=True)
 
+    # Unsandbox API credentials for karaoke vocal isolation
+    unsandbox_public_key = Column(Unicode(128), nullable=True)
+    unsandbox_secret_key = Column(Unicode(128), nullable=True)
+
     created_timestamp = Column(BigInteger, nullable=False)
     updated_timestamp = Column(BigInteger, nullable=False)
 
diff --git a/make_post_sell/scripts/alembic/versions/a1b2c3d4e5f6_add_unsandbox_keys_to_shop.py b/make_post_sell/scripts/alembic/versions/a1b2c3d4e5f6_add_unsandbox_keys_to_shop.py
new file mode 100644
index 0000000..3e5032b
--- /dev/null
+++ b/make_post_sell/scripts/alembic/versions/a1b2c3d4e5f6_add_unsandbox_keys_to_shop.py
@@ -0,0 +1,40 @@
+"""add unsandbox API keys to shop
+
+Revision ID: a1b2c3d4e5f6
+Revises: d4c7d6a1e961
+Create Date: 2026-02-17 00:00:00.000000
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'a1b2c3d4e5f6'
+down_revision = 'd4c7d6a1e961'
+branch_labels = None
+depends_on = None
+
+
+def _column_exists(table, column):
+    conn = op.get_bind()
+    result = conn.execute(sa.text(f"PRAGMA table_info({table})"))
+    return any(row[1] == column for row in result.fetchall())
+
+
+def upgrade():
+    if not _column_exists("mps_shop", "unsandbox_public_key"):
+        op.add_column(
+            "mps_shop",
+            sa.Column("unsandbox_public_key", sa.Unicode(128), nullable=True),
+        )
+    if not _column_exists("mps_shop", "unsandbox_secret_key"):
+        op.add_column(
+            "mps_shop",
+            sa.Column("unsandbox_secret_key", sa.Unicode(128), nullable=True),
+        )
+
+
+def downgrade():
+    op.drop_column("mps_shop", "unsandbox_secret_key")
+    op.drop_column("mps_shop", "unsandbox_public_key")
diff --git a/make_post_sell/scripts/backfill_karaoke.py b/make_post_sell/scripts/backfill_karaoke.py
new file mode 100644
index 0000000..ad1a475
--- /dev/null
+++ b/make_post_sell/scripts/backfill_karaoke.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+"""Backfill vocal isolation tracks for all existing audio/video products.
+
+Usage:
+    python -m make_post_sell.scripts.backfill_karaoke production.ini
+    python -m make_post_sell.scripts.backfill_karaoke production.ini --execute
+"""
+
+import argparse
+import sys
+
+from pyramid.paster import bootstrap
+
+from make_post_sell.models.product import Product, get_media_type
+from make_post_sell.lib.karaoke import process_karaoke, tracks_exist
+
+
+def backfill(env, dry_run=True):
+    request = env["request"]
+    dbsession = request.dbsession
+    s3 = request.secure_uploads_client
+    bucket = request.app["bucket.secure_uploads"]
+
+    products = dbsession.query(Product).all()
+    print(f"Found {len(products)} products to scan")
+    print(f"Dry run: {dry_run}")
+    print("-" * 50)
+
+    processed = 0
+    skipped = 0
+    errors = 0
+
+    for product in products:
+        shop = product.shop
+        if not shop.unsandbox_public_key or not shop.unsandbox_secret_key:
+            continue
+
+        for file_key in ("product", "preview"):
+            ext = product.extensions.get(file_key)
+            if not ext:
+                continue
+            media_type = get_media_type(ext)
+            if media_type not in ("video", "audio"):
+                continue
+
+            s3_key = f"{product.s3_path}/{file_key}"
+
+            if tracks_exist(s3, bucket, product.s3_path):
+                print(f"SKIP {product.title} ({file_key}) — tracks already exist")
+                skipped += 1
+                continue
+
+            if dry_run:
+                print(f"WOULD PROCESS {product.title} ({file_key})")
+                continue
+
+            print(f"PROCESSING {product.title} ({file_key})...")
+            is_video = (media_type == "video")
+            sizes = process_karaoke(
+                s3, bucket, s3_key, product.s3_path, is_video, ext,
+                public_key=shop.unsandbox_public_key,
+                secret_key=shop.unsandbox_secret_key,
+            )
+            if sizes:
+                track_ext = ext if is_video else "wav"
+                for track_name in ("instrumentals", "vocals"):
+                    product.set_file_metadata(track_name, track_ext, f"{track_name}.{track_ext}")
+                tmp = product.file_bytes
+                tmp.update(sizes)
+                product.file_bytes = tmp
+                dbsession.add(product)
+                dbsession.flush()
+                print(f"  OK (instrumentals: {sizes['instrumentals']}B, vocals: {sizes['vocals']}B)")
+                processed += 1
+            else:
+                print(f"  FAILED")
+                errors += 1
+
+    if not dry_run:
+        import transaction
+        transaction.commit()
+
+    print("-" * 50)
+    print(f"Processed: {processed}  Skipped: {skipped}  Errors: {errors}  Dry run: {dry_run}")
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Backfill vocal isolation tracks for audio/video products"
+    )
+    parser.add_argument("config_uri", help="Configuration file (e.g., production.ini)")
+    parser.add_argument(
+        "--execute", action="store_true",
+        help="Actually process files (default is dry run)",
+    )
+    args = parser.parse_args()
+
+    with bootstrap(args.config_uri) as env:
+        try:
+            backfill(env, dry_run=not args.execute)
+        except KeyboardInterrupt:
+            print("\nCancelled")
+            sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/make_post_sell/static/js/player.js b/make_post_sell/static/js/player.js
index d380975..ab79790 100644
--- a/make_post_sell/static/js/player.js
+++ b/make_post_sell/static/js/player.js
@@ -385,6 +385,13 @@
           togglePip();
         }
         break;
+      case 'k':
+      case 'K':
+        e.preventDefault();
+        if (typeof toggleKaraoke === 'function') {
+          toggleKaraoke();
+        }
+        break;
     }
   }
 
diff --git a/make_post_sell/templates/player.j2 b/make_post_sell/templates/player.j2
index d360c10..cda7e8d 100644
--- a/make_post_sell/templates/player.j2
+++ b/make_post_sell/templates/player.j2
@@ -237,7 +237,11 @@
         <!-- Row 3: More options -->
         <button id="autoResizeBtn" onclick="toggleAutoResize()" title="Auto-Resize Window (R)">↔ Resize</button>
         <button onclick="window.close()" title="Close Window (ESC)">✕ Close</button>
-        <span></span><!-- Empty cell for grid alignment -->
+        {% if instrumentals_url or vocals_url %}
+        <button id="karaokeBtn" onclick="toggleKaraoke()" title="Karaoke Mode (K)">🎤 Original</button>
+        {% else %}
+        <span></span>
+        {% endif %}
       </div>
     </div>
   </div>
@@ -252,9 +256,51 @@
       productId: "{{ product.id }}",
       productUrl: "{{ product_url }}",
       prevProductUrl: {{ ('"%s"' % prev_product_url) if prev_product_url else 'null' }},
-      nextProductUrl: {{ ('"%s"' % next_product_url) if next_product_url else 'null' }}
+      nextProductUrl: {{ ('"%s"' % next_product_url) if next_product_url else 'null' }},
+      instrumentalsUrl: {{ ('"%s"' % instrumentals_url) if instrumentals_url else 'null' }},
+      vocalsUrl: {{ ('"%s"' % vocals_url) if vocals_url else 'null' }}
     };
 
+    // Karaoke toggle — cycles: Original → Instrumentals → Vocals → Original
+    let originalSrc = null;
+    const trackModes = [];
+    (function() {
+      trackModes.push({name: 'Original', url: null});
+      if (window.playerData.instrumentalsUrl)
+        trackModes.push({name: 'Instrumentals', url: window.playerData.instrumentalsUrl});
+      if (window.playerData.vocalsUrl)
+        trackModes.push({name: 'Vocals', url: window.playerData.vocalsUrl});
+    })();
+    let trackIndex = 0;
+
+    function toggleKaraoke() {
+      const media = document.getElementById('media');
+      const btn = document.getElementById('karaokeBtn');
+      if (!media || trackModes.length <= 1) return;
+
+      if (!originalSrc) originalSrc = media.src;
+
+      const currentTime = media.currentTime;
+      const wasPlaying = !media.paused;
+
+      trackIndex = (trackIndex + 1) % trackModes.length;
+      const mode = trackModes[trackIndex];
+
+      media.src = mode.url || originalSrc;
+      btn.textContent = '🎤 ' + mode.name;
+      if (trackIndex === 0) {
+        btn.classList.remove('active');
+      } else {
+        btn.classList.add('active');
+      }
+
+      media.addEventListener('loadedmetadata', function once() {
+        media.currentTime = currentTime;
+        if (wasPlaying) media.play();
+        media.removeEventListener('loadedmetadata', once);
+      });
+    }
+
     // Go to the product page (always opens in new tab)
     function goToProductPage() {
       window.open(window.playerData.productUrl, '_blank');
diff --git a/make_post_sell/templates/shop_settings.j2 b/make_post_sell/templates/shop_settings.j2
index dbe442b..37c8971 100644
--- a/make_post_sell/templates/shop_settings.j2
+++ b/make_post_sell/templates/shop_settings.j2
@@ -390,6 +390,73 @@
 <br />
 {% endif %}
 
+<section class="one-column">
+  <section class="shop-settings well">
+
+    <h3>Unsandbox Settings 🎤</h3>
+    <p>API keys for vocal isolation (karaoke mode). Media is processed in zerotrust containers — no network, destroyed after use.</p>
+
+    <form method="post" action="/s/{{ request.shop.id }}/settings" onsubmit="submit.disabled = true; return true;">
+      <input type="hidden" name="form_section" value="unsandbox-settings" />
+
+      <details class="api-key-details">
+      <summary class="toggle-summary">Show Unsandbox API Keys</summary>
+
+      <div class="api-key-fields">
+
+      <br />
+
+      <label for="unsandbox_public_key_input">Public Key</label>
+      <input
+          name        = "unsandbox_public_key"
+          type        = "text"
+          id          = "unsandbox_public_key_input"
+          class       = "full-width-input"
+          value       = "{% if unsandbox_public_key %}{{ unsandbox_public_key }}{% endif %}"
+          placeholder = "unsb-pk-xxxx-xxxx-xxxx-xxxx"
+          />
+
+      <br />
+      <br />
+
+      <label for="unsandbox_secret_key_input">Secret Key</label>
+      <input
+          name        = "unsandbox_secret_key"
+          type        = "text"
+          id          = "unsandbox_secret_key_input"
+          class       = "full-width-input"
+          value       = "{% if unsandbox_secret_key %}{{ unsandbox_secret_key }}{% endif %}"
+          placeholder = "unsb-sk-xxxxx-xxxxx-xxxxx-xxxxx"
+          />
+
+      <br />
+      <br />
+
+      {% if request.shop.unsandbox_public_key and request.shop.unsandbox_secret_key %}
+        <small class="success-indicator">✓ Unsandbox configured — karaoke mode active on new uploads</small>
+      {% else %}
+        <small class="status-message">Add your unsandbox.com API keys to enable vocal isolation on audio/video products.</small>
+      {% endif %}
+
+      <br />
+      <br />
+
+      <input type="submit" name="submit" class="mps-submit" value="Save Unsandbox Settings" />
+
+      </div>
+      </details>
+
+      <br />
+      <br />
+
+    </form>
+
+  </section>
+</section>
+
+<br />
+<br />
+
 {% if request.monero_enabled %}
 <section class="one-column">
   <section class="shop-settings well">
diff --git a/make_post_sell/views/player.py b/make_post_sell/views/player.py
index 5d5fb20..b2176d4 100644
--- a/make_post_sell/views/player.py
+++ b/make_post_sell/views/player.py
@@ -117,6 +117,31 @@ def player(request):
     if next_product_id and current_index is not None and current_index < len(media_products) - 1:
         next_product_url = media_products[current_index + 1].absolute_url(request)
 
+    # Generate presigned URLs for isolated tracks if available
+    instrumentals_url = None
+    vocals_url = None
+    if media_type in ("video", "audio"):
+        for track_name, attr in (("instrumentals", "instrumentals_url"), ("vocals", "vocals_url")):
+            if track_name in product.extensions:
+                track_ext = product.extensions.get(track_name)
+                track_ct = product.get_content_type(track_name) or (
+                    "video/mp4" if media_type == "video" else "audio/wav"
+                )
+                url = request.secure_uploads_client.generate_presigned_url(
+                    ClientMethod="get_object",
+                    Params={
+                        "Bucket": bucket_name,
+                        "Key": f"{product.s3_path}/{track_name}",
+                        "ResponseContentDisposition": f'inline; filename="{product.title} ({track_name.title()}).{track_ext}"',
+                        "ResponseContentType": track_ct,
+                    },
+                    ExpiresIn=900,
+                )
+                if track_name == "instrumentals":
+                    instrumentals_url = url
+                else:
+                    vocals_url = url
+
     return {
         "product": product,
         "presigned_url": presigned_url,
@@ -127,6 +152,8 @@ def player(request):
         "product_url": product_url,
         "prev_product_url": prev_product_url,
         "next_product_url": next_product_url,
+        "instrumentals_url": instrumentals_url,
+        "vocals_url": vocals_url,
     }
 
 
@@ -222,6 +249,31 @@ def player_json(request):
         if current_index < len(media_products) - 1:
             next_product_id = str(media_products[current_index + 1].id)
 
+    # Generate presigned URLs for isolated tracks if available
+    instrumentals_url = None
+    vocals_url = None
+    if media_type in ("video", "audio"):
+        for track_name in ("instrumentals", "vocals"):
+            if track_name in product.extensions:
+                track_ext = product.extensions.get(track_name)
+                track_ct = product.get_content_type(track_name) or (
+                    "video/mp4" if media_type == "video" else "audio/wav"
+                )
+                url = request.secure_uploads_client.generate_presigned_url(
+                    ClientMethod="get_object",
+                    Params={
+                        "Bucket": bucket_name,
+                        "Key": f"{product.s3_path}/{track_name}",
+                        "ResponseContentDisposition": f'inline; filename="{product.title} ({track_name.title()}).{track_ext}"',
+                        "ResponseContentType": track_ct,
+                    },
+                    ExpiresIn=900,
+                )
+                if track_name == "instrumentals":
+                    instrumentals_url = url
+                else:
+                    vocals_url = url
+
     return {
         "success": True,
         "videoUrl": presigned_url,
@@ -230,6 +282,8 @@ def player_json(request):
         "productId": str(product.id),
         "prevProductId": prev_product_id,
         "nextProductId": next_product_id,
+        "instrumentalsUrl": instrumentals_url,
+        "vocalsUrl": vocals_url,
     }
 
 
diff --git a/make_post_sell/views/product.py b/make_post_sell/views/product.py
index 7af8a24..28f0469 100644
--- a/make_post_sell/views/product.py
+++ b/make_post_sell/views/product.py
@@ -365,6 +365,32 @@ def product_edit(request):
                 product.shop.id, request.registry["dbsession_factory"]
             )
 
+        # Generate vocal isolation tracks if this is audio/video
+        from ..models.product import get_media_type
+        from ..lib.karaoke import process_karaoke
+        upload_media_type = get_media_type(product.extensions.get(file_key))
+        shop = product.shop
+        if upload_media_type in ("video", "audio") and shop.unsandbox_public_key and shop.unsandbox_secret_key:
+            is_video = (upload_media_type == "video")
+            ext = product.extensions.get(file_key)
+            sizes = process_karaoke(
+                request.secure_uploads_client,
+                request.app["bucket.secure_uploads"],
+                f"{product.s3_path}/{file_key}",
+                product.s3_path, is_video, ext,
+                public_key=shop.unsandbox_public_key,
+                secret_key=shop.unsandbox_secret_key,
+            )
+            if sizes:
+                track_ext = ext if is_video else "wav"
+                for track_name in ("instrumentals", "vocals"):
+                    product.set_file_metadata(track_name, track_ext, f"{track_name}.{track_ext}")
+                tmp = product.file_bytes
+                tmp.update(sizes)
+                product.file_bytes = tmp
+                request.dbsession.add(product)
+                request.dbsession.flush()
+
         # redirect back to this page to clear
         # the params posted by the s3 webhooks.
         return HTTPFound(f"{product.absolute_edit_url(request)}?uploaded={file_key}")
diff --git a/make_post_sell/views/shop.py b/make_post_sell/views/shop.py
index c93986e..0484751 100644
--- a/make_post_sell/views/shop.py
+++ b/make_post_sell/views/shop.py
@@ -771,6 +771,38 @@ def shop_settings(request):
                     shop.adyen_hmac_key = adyen_hmac_key
                     request.session.flash(("You set the shop's Adyen HMAC Key.", "success"))
 
+        # Handle unsandbox settings form
+        if form_section == "unsandbox-settings":
+            unsandbox_public_key = request.params.get("unsandbox_public_key", "").strip()
+            unsandbox_secret_key = request.params.get("unsandbox_secret_key", "").strip()
+            keys_changed = False
+
+            if unsandbox_public_key and unsandbox_public_key != (shop.unsandbox_public_key or ""):
+                if unsandbox_public_key.startswith("unsb-pk-"):
+                    shop.unsandbox_public_key = unsandbox_public_key
+                    keys_changed = True
+                    request.session.flash(("Unsandbox public key saved.", "success"))
+                else:
+                    request.session.flash(("Unsandbox public key must start with 'unsb-pk-'.", "error"))
+
+            if unsandbox_secret_key and unsandbox_secret_key != (shop.unsandbox_secret_key or ""):
+                if unsandbox_secret_key.startswith("unsb-sk-"):
+                    shop.unsandbox_secret_key = unsandbox_secret_key
+                    keys_changed = True
+                    request.session.flash(("Unsandbox secret key saved.", "success"))
+                else:
+                    request.session.flash(("Unsandbox secret key must start with 'unsb-sk-'.", "error"))
+
+            # Backfill existing catalog when both keys are now present
+            if keys_changed and shop.unsandbox_public_key and shop.unsandbox_secret_key:
+                from ..lib.karaoke import backfill_karaoke_async
+                backfill_karaoke_async(
+                    shop.id,
+                    request.registry["dbsession_factory"],
+                    request.app,
+                )
+                request.session.flash(("Backfilling vocal isolation for existing catalog in background.", "success"))
+
         # Handle maintenance settings form
         if form_section == "maintenance-settings":
             if shop.maint_mode != maint_mode:
@@ -1067,6 +1099,8 @@ def shop_settings(request):
         ),
         "xmr_processor": xmr_processor,
         "doge_processor": doge_processor,
+        "unsandbox_public_key": shop.unsandbox_public_key or "",
+        "unsandbox_secret_key": shop.unsandbox_secret_key or "",
         "signed_posts": signed_posts,
         "get_endpoints": get_endpoints,
     }