diff --git a/data_only_viz/finger_strike.py b/data_only_viz/finger_strike.py
index f59f9bd..1d41fd1 100644
--- a/data_only_viz/finger_strike.py
+++ b/data_only_viz/finger_strike.py
@@ -129,6 +129,7 @@ class FingerStrikeDetector:
 class PinchEvent:
     hand: int          # 0 = left slot (leftmost cx), 1 = right slot
     finger: int        # 1..4 = index, middle, ring, pinky (thumb is trigger)
+    state: int = 1     # 1 = engage edge, 0 = release edge
 
 
 class _PinchState:
@@ -176,13 +177,16 @@ class PinchDetector:
                 if st.engaged:
                     if ratio > self.ratio_off:
                         st.engaged = False
+                        events.append(PinchEvent(hand=slot, finger=i + 1, state=0))
                 elif ratio < self.ratio_on and (
                         t_now - st.last_t) >= self.refractory_s:
                     st.engaged = True
                     st.last_t = t_now
-                    events.append(PinchEvent(hand=slot, finger=i + 1))
+                    events.append(PinchEvent(hand=slot, finger=i + 1, state=1))
         for slot in range(len(self._state)):
             if slot not in present:
                 for i in range(4):
-                    self._state[slot][i].engaged = False
+                    if self._state[slot][i].engaged:
+                        self._state[slot][i].engaged = False
+                        events.append(PinchEvent(hand=slot, finger=i + 1, state=0))
         return events
diff --git a/data_only_viz/pose_bridge.py b/data_only_viz/pose_bridge.py
index c2173a3..7eafb79 100644
--- a/data_only_viz/pose_bridge.py
+++ b/data_only_viz/pose_bridge.py
@@ -398,8 +398,8 @@ class PoseSoundBridge:
         self._vj("/pose/finger", args)
 
     def send_pinch(self, ev) -> None:
-        """Emit one thumb-to-finger pinch event (clip toggle trigger)."""
-        args = [0, int(ev.hand), int(ev.finger)]
+        """Emit a thumb-to-finger pinch edge (state 1=engage, 0=release)."""
+        args = [0, int(ev.hand), int(ev.finger), int(getattr(ev, "state", 1))]
         try:
             self._client.send_message("/pose/pinch", args)
         except OSError:
diff --git a/data_only_viz/tests/test_finger_strike.py b/data_only_viz/tests/test_finger_strike.py
index 1278aae..8169cbb 100644
--- a/data_only_viz/tests/test_finger_strike.py
+++ b/data_only_viz/tests/test_finger_strike.py
@@ -123,3 +123,24 @@ def test_pinch_refractory_blocks():
     b = det.step([_pinch_hand(*_PINCH)], 0.10)  # within 200 ms -> blocked
     assert len(a) == 1
     assert b == []
+
+
+def test_pinch_engage_release_emits_both_edges():
+    """Engage emits state=1; subsequent open emits state=0 (same finger)."""
+    det = PinchDetector(ratio_on=0.45, ratio_off=0.65, refractory_ms=0)
+    det.step([_pinch_hand(*_OPEN)], 0.0)
+    engage = det.step([_pinch_hand(*_PINCH)], 0.1)   # engage edge
+    release = det.step([_pinch_hand(*_OPEN)], 0.2)   # release edge
+    assert len(engage) == 1 and engage[0].state == 1
+    assert len(release) == 1 and release[0].state == 0
+    assert release[0].hand == 0 and release[0].finger == 1
+
+
+def test_pinch_hand_disappear_emits_release():
+    """When an engaged hand disappears, a release edge is synthesised."""
+    det = PinchDetector(ratio_on=0.45, ratio_off=0.65, refractory_ms=0)
+    det.step([_pinch_hand(*_OPEN)], 0.0)
+    engage = det.step([_pinch_hand(*_PINCH)], 0.1)   # engage
+    release = det.step([], 0.2)                       # hand gone
+    assert len(engage) == 1 and engage[0].state == 1
+    assert len(release) == 1 and release[0].state == 0
diff --git a/data_only_viz/tests/test_pose_bridge_finger.py b/data_only_viz/tests/test_pose_bridge_finger.py
index e2f2651..f2b6651 100644
--- a/data_only_viz/tests/test_pose_bridge_finger.py
+++ b/data_only_viz/tests/test_pose_bridge_finger.py
@@ -1,4 +1,4 @@
-"""Tests for PoseSoundBridge.send_finger."""
+"""Tests for PoseSoundBridge.send_finger and send_pinch."""
 from __future__ import annotations
 
 from unittest.mock import MagicMock
@@ -34,3 +34,38 @@ def test_send_finger_emits_expected_osc():
     assert isinstance(args[0], int) and not isinstance(args[0], bool)
     assert isinstance(args[1], int) and isinstance(args[2], int)
     assert all(isinstance(a, float) for a in args[3:7])
+
+
+def test_send_pinch_emits_state_as_4th_arg():
+    """send_pinch must put the edge state (1=engage, 0=release) as 4th arg."""
+    b = _bridge()
+
+    class _FakePinchEvent:
+        hand = 0
+        finger = 1
+        state = 1
+
+    b.send_pinch(_FakePinchEvent())
+    b._client.send_message.assert_called_once()
+    addr, args = b._client.send_message.call_args[0]
+    assert addr == "/pose/pinch"
+    assert args[0] == 0          # pid
+    assert args[1] == 0          # hand
+    assert args[2] == 1          # finger
+    assert args[3] == 1          # state (engage edge)
+    assert len(args) == 4
+
+
+def test_send_pinch_release_state_is_zero():
+    """Release edge: state=0 appears as 4th arg."""
+    b = _bridge()
+
+    class _FakeRelease:
+        hand = 1
+        finger = 2
+        state = 0
+
+    b.send_pinch(_FakeRelease())
+    addr, args = b._client.send_message.call_args[0]
+    assert addr == "/pose/pinch"
+    assert args[3] == 0          # state = release
diff --git a/launcher/concert/launch_concert.sh b/launcher/concert/launch_concert.sh
index 79d419d..c1d4dc8 100755
--- a/launcher/concert/launch_concert.sh
+++ b/launcher/concert/launch_concert.sh
@@ -20,10 +20,9 @@ export PATH=/opt/homebrew/bin:$PATH
 # delegate has headroom and stays fluid AND stable. Override with
 # MEDIAPIPE_DELEGATE=gpu only for short sessions where you accept the crash risk.
 export MEDIAPIPE_DELEGATE="${MEDIAPIPE_DELEGATE:-cpu}"
-# Finger pinches drive the matrix global actions (8 slots). Enabling the pinch
-# detector also enables the air-piano finger-strike detector, inert unless a
-# voice has a finger binding (none by default).
-export FINGER_PIANO="${FINGER_PIANO:-1}"
+# Finger pinches drive the matrix global actions (8 slots). PINCH_ENABLE gates
+# ONLY the pinch detector; the air-piano finger-strike (FINGER_PIANO) stays off.
+export PINCH_ENABLE="${PINCH_ENABLE:-1}"
 export POSE_FILTER=median+kalman+lookahead+ik+arkit_fuse
 # CONCERT_MIRROR=0 in the environment disables the video mirror.