diff --git a/src/sandbox/tuning.py b/src/sandbox/tuning.py
index 4eb1d1a..e3f45e1 100644
--- a/src/sandbox/tuning.py
+++ b/src/sandbox/tuning.py
@@ -57,7 +57,7 @@ def main():
 
     cp = 440
     test = f'test.{cp}.wav'
-    synth(test, a4=cp)
+    synth(test, a4=cp, tenuto=1)
 
     samples, samplerate = soundfile.read(test)