diff -r 9d968fbcaa2a -r 0d7dac03c1a0 utils/pianoroll-client.py
--- a/utils/pianoroll-client.py	Tue Jan 20 12:00:40 2015 +0100
+++ b/utils/pianoroll-client.py	Tue Jan 20 18:37:51 2015 +0100
@@ -7,6 +7,7 @@
 
 import argparse
 import csv
+import signal
 import time
 
 import ntplib
@@ -19,7 +20,7 @@
     """
     Example that sends UDP messages.
     """
-    def __init__(self, port, host, address, rows, shift):
+    def __init__(self, port, host, address, rows, shift, token):
         self.port = port
         self.host = host
         self.client = async.DatagramClientProtocol()
@@ -27,6 +28,7 @@
         self.rows = rows
         self.address = address
         self.shift = shift
+        self.token = token
         reactor.callLater(0, self.send_messages)
 
     def _send(self, element):
@@ -36,19 +38,31 @@
 
     def send_messages(self):
         t0 = time.time()
+        #tc = 0
         for row in self.rows:
+            if not self.token.running:
+                break
             if self.shift:
-                row[0] = ntplib.system_to_ntp_time(t0 + float(row[1])/10**3)
+                row[0] = ntplib.system_to_ntp_time(t0 + float(row[1])/1000.0)
             row_conv = [ osc.TimeTagArgument(float(row[0]))] + [osc.IntArgument(int(a)) for a in row[1:]]
-            #time.sleep((row_conv[1].value-tc)/10**3)
-            time.sleep(0.1)
-            #tc = row_conv[1].value
+            #time.sleep((row_conv[1].value-tc)/1000.0)
+            sleep_time = t0+float(row[1])/1000.0-time.time()
+            if sleep_time > 0:
+                time.sleep(sleep_time)
+            #time.sleep(0.1)
+            tc = row_conv[1].value
             self._send(osc.Message(self.address,*row_conv))
         print("Goodbye.")
         reactor.callLater(0.1, reactor.stop)
 
+class Token(object):
+    def __init__(self):
+        self.running = True
+
 if __name__ == "__main__":
 
+    token = Token()
+
     parser = argparse.ArgumentParser(description='Simulate an (osc) pianoroll client.')
     parser.add_argument('datafile', metavar='DATAFILE', help='The file containing the pianoroll data (CSV).')
     parser.add_argument('-e', '--event', dest='event', metavar='EVENT', required=True, help='the event code.')
@@ -56,8 +70,16 @@
 
     args = parser.parse_args()
 
+    def customHandler(signum, _):
+        print("Got signal: %s" % signum)
+        token.running = False
+        if reactor.running:
+            reactor.callFromThread(reactor.stop) # to stop twisted code when in the reactor loop
+    signal.signal(signal.SIGINT, customHandler)
+
+
     with open(args.datafile, 'rU') as datafile:
         reader = csv.reader(datafile, delimiter=' ')
-        app = UDPSenderApplication(9090, "127.0.0.1", "/pianoroll/%s/" % args.event, list(reader), args.shift)
+        app = UDPSenderApplication(9090, "127.0.0.1", "/pianoroll/%s/" % args.event, list(reader), args.shift, token)
 
     reactor.run()