Blocking False
==============

*Example script* (scamp): `examples/Tutorial/03_blocking_false.py <https://github.com/MarcTheSpark/scamp/blob/main/examples/Tutorial/03_blocking_false.py>`__

*Download:* :download:`03_blocking_false.py <downloads/tutorial_03_blocking_false/03_blocking_false.py>`

By default `play_note` blocks execution until the note is done playing. This is very useful for playing a melody, since you simply call `play_note` in sequence for every note of the melody. However, one simple way of allowing notes to overlap — if desired — is to pass the keyword argument `blocking=False`. This is essentially a single-note fork: playback continues on to the next line without waiting for the note to finish.

*Topics:* :doc:`Time & clocks › Forking & simultaneity <time_clocks>`

.. raw:: html

   <div style="margin:0.6em 0"><audio controls preload="none" src="../_static/media/Tutorial/03_blocking_false.mp3" style="width:100%;max-width:520px"></audio></div>

.. code-block:: python

   # import the scamp namespace
   from scamp import *
   # construct a session object
   s = Session()
   # add a new violin part to the session
   violin = s.new_part("Violin")

   # start playing a 2-beat C, but return immediately
   violin.play_note(60, 1, 2, blocking=False)
   # wait for only one beat
   wait(1)
   # start playing a 2-beat E, blocking this time
   violin.play_note(64, 1, 2)

   for pitch in [67, 72, 60, 64, 67, 72]:
       # play notes that are a whole beat long...
       violin.play_note(pitch, 1, 1, blocking=False)
       # ...waiting only half a beat in between
       wait(0.5)

   # a note is still playing when we reach the end of the script.
   # Without this line, it gets cut off prematurely; this keeps the script alive until it finished
   wait_for_children_to_finish()