.. _usersGuide_03_pitches:

.. WARNING: DO NOT EDIT THIS FILE:
   AUTOMATICALLY GENERATED.
   PLEASE EDIT THE .py FILE DIRECTLY.


User’s Guide, Chapter 3: Pitches, Durations, and Notes again
============================================================

Now that you’ve made a couple of ``Note`` objects, it’s time to dig a
little deeper into what makes a ``Note`` really a ``Note``, namely,
:ref:`modulePitch`, and :ref:`moduleDuration` objects.

The Pitch object
----------------

Since we’ve already covered ``Note`` objects,
:class:`~music21.pitch.Pitch` objects will be a breeze. Just like how
the ``Note`` object is found in the ``note`` module, the ``Pitch``
object is found in the ``pitch`` module.

Let’s create a ``Pitch``. Like we did with ``Notes``, just class the
class with a note name, such as ``B`` with the optional symbols for
sharp or flat, (*#* or *-* respectively).

You can put an octave number after the name (4 = low treble clef), but
you don’t have to:

.. code:: ipython3

    from music21 import *
    p1 = pitch.Pitch('b-4')

Here we’ll use a more abstract variable name, ``p1`` for our first
``Pitch``, just in case we change the pitch later (via ``.transpose()``
or something else).

Just like we saw with ``Notes`` there are a lot of attributes (a.k.a.
properties; we’ll use the term interchangeably for a bit before we talk
about the difference) and methods that describe and change pitches. The
first three will be old hat from ``Note`` objects:

.. code:: ipython3

    p1.octave




.. parsed-literal::
   :class: ipython-result

    4



.. code:: ipython3

    p1.pitchClass




.. parsed-literal::
   :class: ipython-result

    10



.. code:: ipython3

    p1.name




.. parsed-literal::
   :class: ipython-result

    'B-'



.. code:: ipython3

    p1.accidental.alter




.. parsed-literal::
   :class: ipython-result

    -1.0



Here are two more that you can use. The first is pretty
self-explanatory. The second gives the value of the ``Pitch`` in the
older, “MIDI” representation that is still in use today. It’s a number
between 0 and 127 where middle C (C4) is 60 and C#4/Db4 is 61, B3 is 59,
etc.

.. code:: ipython3

    p1.nameWithOctave




.. parsed-literal::
   :class: ipython-result

    'B-4'



.. code:: ipython3

    p1.midi




.. parsed-literal::
   :class: ipython-result

    70



Most of these attributes can be changed (they are “settable properties”
in Python speak).

When an attribute is set, the ``Pitch`` object changes whatever is
necessary to reflect the new value:

.. code:: ipython3

    p1.name = 'd#'
    p1.octave = 3
    p1.nameWithOctave




.. parsed-literal::
   :class: ipython-result

    'D#3'



And our familiar ``.transpose()`` method also appears on ``Pitch`` as
well. Remember that ``p1`` is now a ``D#``:

.. code:: ipython3

    p2 = p1.transpose('M7')
    p2




.. parsed-literal::
   :class: ipython-result

    <music21.pitch.Pitch C##4>



Notice that at the command line, just printing the variable name gives
you the representation ``<music21.pitch.Pitch C##4>``. You can also get
this by typing ``repr(p2)``.

So, there’s really nothing new about ``Pitch`` objects that you didn’t
already know from learning about ``Notes``. So why the two different
objects? It turns out, they are so similar because actually every
``Note`` object has a ``Pitch`` object inside it (like the monster in
*Alien* but more benign). Everything that we did with the ``note.Note``
object, we could do with the ``note.Note.pitch`` object instead:

.. code:: ipython3

    csharp = note.Note('C#4')
    csharp.name




.. parsed-literal::
   :class: ipython-result

    'C#'



.. code:: ipython3

    csharp.pitch.name




.. parsed-literal::
   :class: ipython-result

    'C#'



.. code:: ipython3

    csharp.octave




.. parsed-literal::
   :class: ipython-result

    4



.. code:: ipython3

    csharp.pitch.octave




.. parsed-literal::
   :class: ipython-result

    4



But pitch objects have a lot more to offer for more technical working,
for instance, ``Pitch`` objects know their names in Spanish:

.. code:: ipython3

    csharp.pitch.spanish




.. parsed-literal::
   :class: ipython-result

    'do sostenido'



Notes don’t:

.. code:: ipython3

    csharp.spanish


::


    ---------------------------------------------------------------------------

    AttributeError                            Traceback (most recent call last)

    <ipython-input-16-a0f0e2502262> in <module>
    ----> 1 csharp.spanish
    

    AttributeError: 'Note' object has no attribute 'spanish'


Here are some other things you can do with Pitch objects. Get the sharp
printed nicely:

.. code:: ipython3

    print(csharp.pitch.unicodeName)


.. parsed-literal::
   :class: ipython-result

    C♯


Get some enharmonics – these are methods, so we add ``()`` to them:

.. code:: ipython3

    print( csharp.pitch.getEnharmonic() )
    print( csharp.pitch.getLowerEnharmonic() )


.. parsed-literal::
   :class: ipython-result

    D-4
    B##3


*By the way, you know how we said that you shouldn’t have a variable
named* ``pitch`` *because there’s already a module named* ``pitch``.
*You might wonder why* ``Note`` *objects can have an attribute named*
``pitch`` *without causing any problems. It’s because the* ``.pitch``
*attribute is always attached to a* ``Note`` *, so it’s never used
without a prefix of some sort (in this case,* ``csharp.pitch`` *), and
that’s enough to prevent any trouble.*

So far, it looks like ``Pitch`` objects can do everything ``Note``
objects can do and more. So why do we need ``Note`` objects? It’s
because they also have ``Duration`` attributes, as we’ll see in the next
section. Without a ``Duration`` attribute, you cannot put an object into
a Measure or show it on your screen.

Carving time with Duration objects
----------------------------------

For a ``Note`` to occupy musical space, it has to last a certain amount
of time. We call that time the ``Note``\ ’s
:class:`~music21.duration.Duration`. ``Duration`` objects are
ubiquitous in music21. Nearly all objects have, or can have, a
``Duration``. A ``Duration`` object can represent just about any time
span.

``Duration`` objects are best used when they’re attached to something
else, like a ``Note`` or a ``Rest``, but for now, let’s look at what we
can do with them on their own.

``Duration`` objects reside in the ``duration`` module. When you create
a ``Duration`` object, you can say what type of duration you want it to
be when you create it.

Here we’ll create the duration of a half note:

.. code:: ipython3

    halfDuration = duration.Duration('half')

The string “half” is called the “type” of the ``Duration``. Music21
``Durations`` use the common American duration types: “whole”, “half”,
“quarter”, “eighth”, “16th”, “32nd”, “64th”. Note that for durations
shorter than an eighth note, we use numbers instead of spelling out the
whole name of the ``Duration`` type. Music21 also supports less commonly
used types such as “breve” (2 whole notes), “longa” (4 whole notes), and
“maxima” (8 whole notes) and on the other side, “128th”, “256th”, etc.
down to “2048th” notes. (Some of these very long and very short notes
can’t be displayed in many musical notation systems, but it’s good to
know that we’re ready when they are).

The other standard way of creating a ``Duration`` is by passing it a
number when it is created. That number represents how many quarter notes
long it is. So we could have created our half note ``Duration`` by
saying ``2`` or ``2.0``. But we can also create ``Durations`` that
aren’t exactly “whole”, “half”, “quarter”, etc. Let’s create a dotted
quarter note, which is 1.5 quarter notes long:

.. code:: ipython3

    dottedQuarter = duration.Duration(1.5)

As with the ``Pitch`` and ``Note`` objects we’ve already seen, there are
a bunch of attributes that ``Duration`` objects have. The most important
one is ``.quarterLength``. The
:attr:`~music21.duration.Duration.quarterLength` of our
``dottedQuarter`` variable is of course 1.5: we set it to be. But just
as importantly, the ``halfDuration`` object also has its quarterLength
set:

.. code:: ipython3

    dottedQuarter.quarterLength




.. parsed-literal::
   :class: ipython-result

    1.5



.. code:: ipython3

    halfDuration.quarterLength




.. parsed-literal::
   :class: ipython-result

    2.0



The ``.type`` attribute tells you what general type of ``Duration`` you
have:

.. code:: ipython3

    halfDuration.type




.. parsed-literal::
   :class: ipython-result

    'half'



.. code:: ipython3

    dottedQuarter.type




.. parsed-literal::
   :class: ipython-result

    'quarter'



The ``type`` attribute cannot be everything that describes the
``Duration``, there has to be some place where music21 keeps track of
the fact that the ``dottedQuarter`` variable has a dot (otherwise it
wouldn’t have a ``quarterLength`` of 1.5). You’ll find the attribute
called ``.dots``:

.. code:: ipython3

    halfDuration.dots




.. parsed-literal::
   :class: ipython-result

    0



.. code:: ipython3

    dottedQuarter.dots




.. parsed-literal::
   :class: ipython-result

    1



The attributes of ``dots``, ``type``, and ``quarterLength`` are actually
special attributes called “properties”. A property is an attribute that
is smart in some way. Let’s change the number of dots on our
``dottedQuarter`` object and see what happens to the ``quarterLength``
property:

.. code:: ipython3

    dottedQuarter.dots = 2
    dottedQuarter.quarterLength




.. parsed-literal::
   :class: ipython-result

    1.75



.. code:: ipython3

    dottedQuarter.dots = 3
    dottedQuarter.quarterLength




.. parsed-literal::
   :class: ipython-result

    1.875



.. code:: ipython3

    dottedQuarter.dots = 4
    dottedQuarter.quarterLength




.. parsed-literal::
   :class: ipython-result

    1.9375



Or let’s change the ``quarterLength`` of the dottedQuarter and see what
happens to the ``type`` and ``dots``:

.. code:: ipython3

    dottedQuarter.quarterLength = 0.25
    dottedQuarter.type




.. parsed-literal::
   :class: ipython-result

    '16th'



.. code:: ipython3

    dottedQuarter.dots




.. parsed-literal::
   :class: ipython-result

    0



QuarterLengths are so important to music21 that we’ll sometimes
abbreviate them as ``qL`` or ``qLs``. Almost everything that is measured
in music21 is measured in ``qLs``.

Music21 can also deal with other ``quarterLengths`` such as 0.8, which
is 4/5ths of a quarter note, or 1/3, which is an eighth note triplet.
(For this reason, users compiling spreadsheets or other text-based
output should expect to find the occasional ``quarterLength`` expressed
as a ``Fraction``.)

(You can go ahead and make a triplet or other
:class:`~music21.duration.Tuplet`, but we’ll get to triplets,
including tips for manipulating a ``Fraction`` in Chapter 19).

Back to Notes
-------------

So now you can see the advantage of working with ``Note`` objects: they
have both a ``.pitch`` attribute, which contains a ``Pitch`` object, and
a ``.duration`` attribute, which contains a ``Duration`` object. The
default ``Pitch`` for a ``Note`` is ``C`` (meaning ``C4``) and the
default ``Duration`` is 1.0, or a quarter note.

.. code:: ipython3

    n1 = note.Note()
    n1.pitch




.. parsed-literal::
   :class: ipython-result

    <music21.pitch.Pitch C4>



.. code:: ipython3

    n1.duration




.. parsed-literal::
   :class: ipython-result

    <music21.duration.Duration 1.0>



But we can play around with them:

.. code:: ipython3

    n1.pitch.nameWithOctave = 'E-5'
    n1.duration.quarterLength = 3.0

and then the other properties change accordingly:

.. code:: ipython3

    n1.duration.type




.. parsed-literal::
   :class: ipython-result

    'half'



.. code:: ipython3

    n1.duration.dots




.. parsed-literal::
   :class: ipython-result

    1



.. code:: ipython3

    n1.pitch.name




.. parsed-literal::
   :class: ipython-result

    'E-'



.. code:: ipython3

    n1.pitch.accidental




.. parsed-literal::
   :class: ipython-result

    <music21.pitch.Accidental flat>



.. code:: ipython3

    n1.octave




.. parsed-literal::
   :class: ipython-result

    5



We already said that some of the attributes of ``Pitch`` can also be
called on the ``Note`` object itself. The same is true for the most
important attributes of ``Duration``:

.. code:: ipython3

    n1.name




.. parsed-literal::
   :class: ipython-result

    'E-'



.. code:: ipython3

    n1.quarterLength




.. parsed-literal::
   :class: ipython-result

    3.0



Let’s change the quarterLength back to 1.0 for now:

.. code:: ipython3

    n1.quarterLength = 1.0

``Notes`` can do things that neither ``Pitch`` or ``Duration`` objects
can do. For instance, they can have lyrics. Let’s add some lyrics to
``Notes``. You can easily set :class:`~music21.note.Lyric` objects
just by setting the :meth:`lyric <music21.note.GeneralNote.lyric>`
property. (For reference, the ``lyric`` attribute is actually an
attribute of :class:`~music21.note.GeneralNote`, which is a “base
class” from which the ``Note`` class “inherits”. In other words, the
``Note`` class gains the ``lyric`` attribute from ``GeneralNote``. But
that’s not too important.)

.. code:: ipython3

    otherNote = note.Note("F6")
    otherNote.lyric = "I'm the Queen of the Night!"

But let’s do something more complex. Here I add multiple lyrics to
``n1`` using the ``Note's`` :meth:`~music21.note.GeneralNote.addLyric`
method. And instead of adding a simple String, I’ll add as a lyric the
name of the note itself and its ``pitchClassString``.

.. code:: ipython3

    n1.addLyric(n1.nameWithOctave)
    n1.addLyric(n1.pitch.pitchClassString)

Finally, lets put the ``quarterLength`` of the note as a string with a
preface “QL:”:

.. code:: ipython3

    n1.addLyric(f'QL: {n1.quarterLength}')

The placement of an “f” before the string
``f'QL: {n1.quarterLength}``\ ’ says to substitute anything in ``{}``
with its actual value as a string. (Remember that ``.quarterLength`` is
not a string, but a float).

As it should be becoming clear, we can always check our work with the
:meth:`~music21.base.Music21Object.show` method.

.. code:: ipython3

    n1.show()



.. image:: usersGuide_03_pitches_85_0.png
   :width: 262px
   :height: 91px


If we now edit the
:meth:`quarterLength <music21.base.Music21Object.quarterLength>`
property we can still change the ``Note``\ ’s ``Duration``. But because
we already set the lyric to show “\ ``QL: 1.0``, it won’t be changed
when we ``.show()`` it again in the following example.

.. code:: ipython3

    n1.quarterLength = 6.25
    n1.show()



.. image:: usersGuide_03_pitches_87_0.png
   :width: 281px
   :height: 91px


There are many more things we can do with a ``Note`` object, but I’m
itching to look at what happens when we put multiple ``Notes`` together
in a row. And to do that we’ll need to learn a bit about the topic of
:ref:`Chapter 4: Streams <usersGuide_04_stream1>`.