Abstract Base
=============

The :class:`AbstractBase` class is the abstract base class for all
pitch and interval types of the library. It provides some shared
functionality and properties.

Basic Attributes
----------------

is_pitch

is_interval

is_class

value

Creating and Linking Sub-Types
------------------------------

Type Conversion
---------------

Basic Functionality
-------------------

Comparison and Equality
^^^^^^^^^^^^^^^^^^^^^^^

Printing
^^^^^^^^

Hashing
^^^^^^^