The algorithm to analyze the chord progressions of a piece of music

In algorithms module of musicpy, there are a chord progression analysis algorithm implemented to analyze the chord progressions of a piece of music or a fragment of music. The algorithm is implemented in chord_analysis function, along with chord_functions_analysis function which further analyzes each chord's function in a given scale.

Note that this algorithm is in experimental stage, and is not expected to perform well on every situation of a piece of music.

The chord_analysis function analyzes and outputs each chord splitted from the given chord instance (which represents a fragment of music).

Usage

chord_analysis(chords,
               mode='chord names',
               is_chord=False,
               new_chord_tol=database.minor_seventh,
               get_original_order=False,
               formatted=False,
               formatted_mode=1,
               output_as_file=False,
               each_line_chords_number=5,
               functions_interval=1,
               split_symbol='|',
               space_lines=2,
               detect_args={},
               split_chord_args={})

• chords: a chord instance to be analyzed
• mode: the output mode, here are the options:
• 'chords': get the chord instances of each chord
• 'chord names': get the chord names of each chord
• 'inds': get the indexes of each chord
• 'bars': get the bar ranges of each chord
• 'bars start': get the start bars of each chord
• is_chord: if set to False, the algorithm will firstly perform a melody and chord split operation to the given chord instance, if set to True, use the given chord instance directly to analyze
• new_chord_tol: the new chord tolerance, pitch interval
• get_original_order: if set to True, get the original order of each chord that appears in the given chord instance
• formatted: if set to True, format the output results
• formatted_mode: format mode for the output string, could be 0 or 1
• output_as_file: when formatted is set to True, set this parameter to True to output the results as file
• each_line_chords_number: the number of chords in each line in the output string
• functions_interval: the number of spaces between each 2 chords in the output string
• split_symbol: the split symbol between each 2 chords in the output string
• space_lines: the number of empty lines between each 2 lines in the output string
• detect_args: the arguments for detect function
• split_chord_args: the arguments for split_chord function

Examples

import musicpy as mp
current_piece = mp.read('test.mid')
current_chord, current_bpm, current_start_time = current_piece.merge()
current_chord_progressions = mp.alg.chord_analysis(current_chord)
>>> print(current_chord_progressions)
['Dm7 omit F', 'Bm7 sort as [1, 3, 4, 2]', 'Em7 omit G', 'Dm7 omit F']