diff --git a/src/osc_sender.py b/src/osc_sender.py
index c022efb..b1c67ce 100644
--- a/src/osc_sender.py
+++ b/src/osc_sender.py
@@ -91,6 +91,13 @@ class OSCSender:
         msg.add_arg(freq)
         self.client.send(msg.build())
 
+    def send_single(self, frequency, voice):
+        """Send a single frequency to a specific voice (1-indexed)."""
+        msg = osc_message_builder.OscMessageBuilder(address="/freq")
+        msg.add_arg(voice)  # Voice number (1-indexed)
+        msg.add_arg(frequency)
+        self.client.send(msg.build())
+
     def send_current(self):
         """Send all voices at their current positions."""
         for voice_idx in range(self.num_voices):
diff --git a/supercollider/osc_receiver.scd b/supercollider/osc_receiver.scd
new file mode 100644
index 0000000..517caab
--- /dev/null
+++ b/supercollider/osc_receiver.scd
@@ -0,0 +1,36 @@
+// osc_receiver.scd - OSC receiver for webapp
+// Run this in SuperCollider: sclang supercollider/osc_receiver.scd
+// Then click nodes in the webapp to play tones
+
+s.boot;
+s.waitForBoot {
+    
+    // Define synth on the server (2-second ring)
+    SynthDef(\sineTone, {
+        |freq = 440, amp = 0.15|
+        var env = EnvGen.kr(
+            Env([0, 1, 1, 0], [0.05, 0.1, 1.85], \sin),
+            doneAction: Done.freeSelf
+        );
+        Out.ar(0, SinOsc.ar(freq) * env * amp);
+    }).add;
+    
+    // Wait for synth to be added to server
+    s.sync;
+    
+    // OSC handler for /freq messages
+    ~oscHandler = OSCFunc({ |msg, time, addr, recvPort|
+        if (msg.size >= 3, {
+            var freq = msg[2].asFloat;
+            if (freq > 0, {
+                Synth(\sineTone, [\freq, freq, \amp, 0.15]);
+            });
+        });
+    }, '/freq');
+    
+    "OSC receiver ready on port 57120".postln;
+    "Click nodes in webapp to play".postln;
+    
+    // Keep alive
+    while { true } { 10.wait; };
+}
\ No newline at end of file
diff --git a/webapp/path_navigator.html b/webapp/path_navigator.html
index 6dda9c4..10555a6 100644
--- a/webapp/path_navigator.html
+++ b/webapp/path_navigator.html
@@ -277,6 +277,9 @@
             <button onclick="loadSelectedFile()">Load</button>
             <span style="margin-left: 10px;">or upload:</span>
             <input type="file" id="fileInput" accept=".json">
+            <span style="margin-left: 20px;">Fundamental (Hz):</span>
+            <input type="number" id="fundamentalInput" value="110" style="width: 60px;">
+            <button onclick="setFundamental()">Set</button>
         </div>
         
         <div class="controls">
@@ -385,18 +388,66 @@
             });
             
             // Lock y on drag - only allow x movement
+            let isDragging = false;
+            let grabPosition = null;
+            
             cy.on('grab', 'node', function(evt) {
+                console.log('GRAB event');
                 const node = evt.target;
-                node.data('originalY', node.position('y'));
+                grabPosition = node.position('y');
+                node.data('originalY', grabPosition);
             });
             
             cy.on('drag', 'node', function(evt) {
                 const node = evt.target;
                 const originalY = node.data('originalY');
+                
+                // Only mark as dragging if it actually moved from grab position
+                if (grabPosition !== null && Math.abs(node.position('y') - grabPosition) > 1) {
+                    isDragging = true;
+                }
+                
                 if (originalY !== undefined) {
                     node.position('y', originalY);
                 }
             });
+            
+            cy.on('dragfree', 'node', function(evt) {
+                console.log('DRAGFREE event');
+                isDragging = false;
+                grabPosition = null;
+            });
+            
+            // Click to play - send OSC
+            cy.on('tap', 'node', function(evt) {
+                console.log('TAP event fired', isDragging);
+                
+                const node = evt.target;
+                console.log('Node data:', node.data());
+                
+                if (isDragging) {
+                    console.log('Was dragging, skipping');
+                    return;
+                }
+                
+                const chordIndex = node.data('chordIndex');
+                const localId = node.data('localId');
+                
+                console.log('Sending play request:', chordIndex, localId);
+                
+                fetch('/api/play-freq', {
+                    method: 'POST',
+                    headers: {'Content-Type': 'application/json'},
+                    body: JSON.stringify({
+                        chordIndex: chordIndex,
+                        nodeIndex: localId
+                    })
+                }).then(r => r.json()).then(data => {
+                    console.log('Playing:', data.frequency.toFixed(2), 'Hz on voice', data.voice);
+                }).catch(err => {
+                    console.log('Error playing freq:', err);
+                });
+            });
         }
         
         // Render all three chords using Cytoscape (legacy - not used with all-chords approach)
@@ -734,6 +785,26 @@
             }
         }
         
+        async function setFundamental() {
+            const input = document.getElementById("fundamentalInput");
+            const fundamental = parseFloat(input.value);
+            if (!fundamental || fundamental <= 0) {
+                alert("Please enter a valid positive number");
+                return;
+            }
+            try {
+                const response = await fetch("/api/set-fundamental", {
+                    method: "POST",
+                    headers: {"Content-Type": "application/json"},
+                    body: JSON.stringify({ fundamental: fundamental })
+                });
+                const data = await response.json();
+                console.log("Fundamental set to:", data.fundamental, "Hz");
+            } catch (e) {
+                console.log("Error setting fundamental", e);
+            }
+        }
+        
         async function loadFromLocalFile() {
             try {
                 const response = await fetch("output/output_chords.json");
diff --git a/webapp/server.py b/webapp/server.py
index 865083b..6cf6ee8 100644
--- a/webapp/server.py
+++ b/webapp/server.py
@@ -14,6 +14,7 @@ import sys
 sys.path.insert(0, str(Path(__file__).parent.parent))
 
 from src.pitch import Pitch
+from src.osc_sender import OSCSender
 from fractions import Fraction
 
 app = Flask(__name__)
@@ -27,6 +28,10 @@ current_index = 0
 chords = []
 dims = (2, 3, 5, 7)
 
+# OSC settings
+fundamental = 110.0
+osc_sender = OSCSender(ip="127.0.0.1", port=57120, fundamental=fundamental)
+
 
 def get_chords_file():
     return DATA_DIR / DATA_FILE
@@ -281,6 +286,47 @@ def reload():
     return jsonify({"loaded": len(chords), "index": current_index})
 
 
+@app.route("/api/set-fundamental", methods=["POST"])
+def set_fundamental():
+    """Set the fundamental frequency for OSC playback."""
+    global fundamental, osc_sender
+    data = request.json
+    fundamental = data.get("fundamental", 110.0)
+    osc_sender = OSCSender(ip="127.0.0.1", port=57120, fundamental=fundamental)
+    return jsonify({"fundamental": fundamental})
+
+
+@app.route("/api/play-freq", methods=["POST"])
+def play_freq():
+    """Play a single frequency for a node."""
+    data = request.json
+    chord_index = data.get("chordIndex")
+    node_index = data.get("nodeIndex")
+
+    if chord_index < 0 or chord_index >= len(chords):
+        return jsonify({"error": "Invalid chord index"}), 400
+
+    chord = chords[chord_index]
+    if node_index < 0 or node_index >= len(chord):
+        return jsonify({"error": "Invalid node index"}), 400
+
+    pitch = chord[node_index]
+    fraction = Fraction(pitch.get("fraction", "1"))
+    frequency = fundamental * float(fraction)
+    voice = node_index + 1  # 1-indexed
+
+    osc_sender.send_single(frequency, voice)
+
+    return jsonify(
+        {
+            "frequency": frequency,
+            "voice": voice,
+            "fundamental": fundamental,
+            "fraction": pitch.get("fraction", "1"),
+        }
+    )
+
+
 if __name__ == "__main__":
     print("Starting Path Navigator server...")
     print(f"Loading chords from: {get_chords_file()}")