:orphan:

Notating Computer Keyboard Input
================================

*Example script* (scamp): `examples/Notation & engraving/From live input/keyboard_input_with_notation.py <https://github.com/MarcTheSpark/scamp/blob/main/examples/Notation & engraving/From live input/keyboard_input_with_notation.py>`__

*Download:* :download:`keyboard_input_with_notation.py <downloads/notation_engraving_from_live_input_keyboard_input_with_notation/keyboard_input_with_notation.py>`

(WARNING: consumes key events and makes the keyboard otherwise unresponsive. To avoid this, you can remove the suppress=True flag under register_keyboard_listener) Same as Computer Keyboard Input, except that a metronome is playing back while the user plays notes with the keyboard, and the result is rendered as music notation.

*Topics:* :doc:`Notation & engraving › From live input <notation_engraving>`, :doc:`Interactivity & visualization › Keyboard input <interactivity_visualization>`

.. raw:: html

   <iframe src="https://www.youtube-nocookie.com/embed/Wb6ZSWIvci8" style="width:100%;max-width:640px;aspect-ratio:16/9;border:0;display:block;margin:0.6em 0" allowfullscreen></iframe>

.. code-block:: python

   from scamp import *

   s = Session()

   piano = s.new_part("piano")
   perc = s.new_part("power")
   s.start_transcribing(piano)

   # dictionary mapping keys that are down to the NoteHandles used to manipulate them.
   notes_started = {}


   def key_down(name, number):
       if number == 27:
           s.kill()
           return

       if 20 < number < 110 and number not in notes_started:
           notes_started[number] = piano.start_note(number, 0.5)


   def key_up(name, number):
       if 20 < number < 110 and number in notes_started:
           notes_started[number].end()
           del notes_started[number]


   def metro():
       while True:
           perc.play_note(60, 1, 1)


   fork(metro)

   # note: suppress=True causes keyboard events to be consumed by this script, effectively disabling the keyboard
   s.register_keyboard_listener(on_press=key_down, on_release=key_up, suppress=True)

   with s:
       # the context manager captures clock (session) kill gracefully, but we also need to
       # catch a KeyboardInterrupt if we want to build the score on ctrl-C
       try:
           wait_forever()
       except KeyboardInterrupt:
           pass

   s.stop_transcribing().to_score().show()