- This projection was born out of enthusiasm
- Enthusiasm about music and different ways to describe it
using one of many music theories.
- Enthusiasm about the Python
- This project was born out of frustration
- Existing open source auto-accompaniment systems typically
specify chords using chord names
despite lists of note names feeling more natural to me.
- Not many people have open sourced their code to recognize
chords --- or if they have, they hid it well.
Many projects, on the other hand, have some plans to add chord
recognition capabilities to their system in the "future".
- The library provides in a number of classes which offer the
- transformation of a list of note names to a chord name:
e.g. ['a', 'c#', 'e', 'g'] => A7
are indicated using a slash and the root note.
e.g. ['e', 'g', 'a', 'c#'] => A7 / E
Chord recognition (for pragmatic reasons) ignores the difference
between e.g. 'f#' and 'gb'.
- Alternatively one can also recognize intervals.
Recognition here does take
into account the difference between e.g. 'f#' and 'gb'.
e.g. ['c','f#'] => 'augmented fourth' or ['c', 'gb'] =>
- Intervals and chords can be transposed:
e.g. ['c','e'] transposed to 'f#' => ['f#','a#']
['c','e'] transposed to 'gb'
- For now, internally the library works with note names 'a',
'b', 'c', 'd', 'e', 'f', 'g'
and modifiers '#' (sharp), 'b' (moll), 'x' (double sharp), 'bb' (double
in its current form is very much in Alpha-state.
- PyChoReLib can already recognize and name hundreds of
- New chords
can be taught to the
system "by example".
e.g. teach the system that ['c','e','g'] is called 'C', and using its
built-in music theory
knowledge it immediately knows how to recognize and label all major
chords in all inversions or (more generally) permutations.
- Once chord recognition definitions have been taught to the
they can be saved to file,
allowing for quick initialization of the
- Intervals and chords can be transposed.
- PyChoReLib comes with two demo programs:
- test.py: tests
the functionality offered by the library using Python's unit testing
converts midi input from
midi devices (ALSA for linux, MME for win32) to chord names
NOTE: This latter program
needs the PyPortMidi software package to be installed and
- Extending the chord recognition database with new chord
- Build in more music theory knowledge to automatically
recognize more chords, while
requiring less teaching.
(Based on matching notes to scales?)
- Add functionality to suggest a scale which can be used to
improvise over a chord
- Extensions to the midiinput proof of concept:
- a teach mode in which the system can be taught new chords
- a GUI
- proof of concept auto-arranger capabilities
- Add support for alternative note names
|(As you may have
guessed, I suck at web design, which explains why this pages loads so
fast and displays properly in most browsers.)
Please use the sourceforge
infrastructure for communication about this project.
There be screenshots!