Tempo Change
============

*Example script* (scamp): `examples/Tutorial/02_tempo_change.py <https://github.com/MarcTheSpark/scamp/blob/main/examples/Tutorial/02_tempo_change.py>`__

*Download:* :download:`02_tempo_change.py <downloads/tutorial_02_tempo_change/02_tempo_change.py>`

Same as Hello World example, but repeatedly, with changing tempi.

*Topics:* :doc:`Time & clocks › Setting & changing tempo <time_clocks>`

.. raw:: html

   <div style="margin:0.6em 0"><audio controls preload="none" src="../_static/media/Tutorial/02_tempo_change.mp3" style="width:100%;max-width:520px"></audio></div>

.. code-block:: python

   from scamp import *

   s = Session()

   # Start with an initial tempo of 100
   s.tempo = 100

   # add a new violin part to the session
   violin = s.new_part("Violin")


   for pitch in [60, 64, 67, 72]:
       violin.play_note(pitch, 1, 0.5)

   # you can change tempo at any time; not just at the beginning
   s.tempo = 40
   for pitch in [60, 64, 67, 72]:
       violin.play_note(pitch, 1, 0.5)

   # you can also do an accelerando/decelerando, specifying
   # a moment at which to reach the goal tempo
   set_tempo_target(150, Moment.after_beats(6))
   for pitch in [60, 64, 67, 72] * 4:
       violin.play_note(pitch, 1, 0.5)