Measuring Pitch Usage Frequency in MIDI Files

In [1]:

    

from __future__ import division
import os
import glob
from collections import Counter

import midi
import numpy as np
import joblib


    

In [2]:

    

def compute_pitch_statistics(midi_file):
    """

    :param midi_file: str - path to a MIDI file
    :return:
    """
    try:
        pattern = midi.read_midifile(midi_file)
        return [
            event.get_pitch()
            for track in pattern
            for event in track if isinstance(event, midi.NoteEvent)
            ]
    except Exception as e:
        pass


    

In [3]:

    

pitch_statistics = joblib.Parallel(n_jobs=10, verbose=0)(
    joblib.delayed(compute_pitch_statistics)(midi_file)
    for midi_file in glob.glob(
        os.path.join(os.path.expanduser("~"), "Lab", "Data", "MIDIs", "*", "*.[mM][iI][dD]"))
)


counter = Counter()
for ps in pitch_statistics:
    counter.update(Counter(ps))
    

notes, frequencies = np.array(counter.keys()), np.array(counter.values())


    

In [87]:

    

import matplotlib.pyplot as plt
%matplotlib inline

plt.rcParams["figure.figsize"] = (12, 6)
# mpl.rcParams['font.sans-serif'] = ['SimHei']  #指定默认字体, 解决中文显示问题


    

In [117]:

    

plt.bar(notes, frequencies / frequencies.sum(), width=1, color="#5fc4fc", linewidth=0.1)

plt.grid(axis="y")
plt.xlim([0, 144])
plt.ylim([0, 0.055])
plt.title("Usage frequency of pitch in Muscic Composition")
plt.xlabel("Pitch")
plt.ylabel("Usage frequency")


    

    
Out[117]:





<matplotlib.text.Text at 0x7ff98e14fa50>






    

In [118]:

    

plt.bar(notes[21:109], frequencies[21:109] / frequencies[21:109].sum(), width=1, color="#5fc4fc", linewidth=0.1)

plt.grid(axis="y")
plt.xlim([21, 109])
plt.ylim([0, 0.055])
plt.title("Usage frequency of pitch in Muscic Composition (Piano pitches)")
plt.xlabel("Pitch")
plt.ylabel("Usage frequency")
plt.show()


    

In [123]:

    

piano_frequencies = frequencies[21: 109] / frequencies[21: 109].sum()
scientific_names = ["A0","A#0","B0","C1","C#1","D1","D#1","E1","F1","F#1","G1","G#1","A1","A#1","B1","C2","C#2","D2","D#2","E2","F2","F#2","G2","G#2","A2","A#2","B2","C3","C#3","D3","D#3","E3","F3","F#3","G3","G#3","A3","A#3","B3","C4","C#4","D4","D#4","E4","F4","F#4","G4","G#4","A4","A#4","B4","C5","C#5","D5","D#5","E5","F5","F#5","G5","G#5","A5","A#5","B5","C6","C#6","D6","D#6","E6","F6","F#6","G6","G#6","A6","A#6","B6","C7","C#7","D7","D#7","E7","F7","F#7","G7","G#7","A7","A#7","B7","C8"]
for name, frequency in zip(scientific_names, piano_frequencies):
    print(name, frequency)


    

    




('A0', 0.00010303542578920389)
('A#0', 6.6589526870013867e-05)
('B0', 0.00014487177774942202)
('C1', 0.00040650988654678623)
('C#1', 0.00022798130000885536)
('D1', 0.00080172932169918026)
('D#1', 0.0010207533514806555)
('E1', 0.0026584051671541941)
('F1', 0.002518280206261797)
('F#1', 0.0015044995801078444)
('G1', 0.0045275782818486069)
('G#1', 0.0019367012776660979)
('A1', 0.0056636766011375307)
('A#1', 0.0033089872583099197)
('B1', 0.017356668792275164)
('C2', 0.028130897148922342)
('C#2', 0.0074038811154622701)
('D2', 0.025765507354535675)
('D#2', 0.0062229159905134463)
('E2', 0.023193617617781263)
('F2', 0.008775657550793757)
('F#2', 0.053685586835022586)
('G2', 0.013145518149387208)
('G#2', 0.01418933513079465)
('A2', 0.019073326949535115)
('A#2', 0.012934056844767771)
('B2', 0.011486143612503556)
('C3', 0.015009461720086593)
('C#3', 0.0084878985401955886)
('D3', 0.019709105408458764)
('D#3', 0.020491016099325507)
('E3', 0.020698561950492255)
('F3', 0.015014342627815284)
('F#3', 0.023841759255072644)
('G3', 0.028366494810441904)
('G#3', 0.015871424661338753)
('A3', 0.035088470207126951)
('A#3', 0.015933803734838412)
('B3', 0.033862718731041228)
('C4', 0.03446411629046936)
('C#4', 0.021478729460027324)
('D4', 0.04371504552680093)
('D#4', 0.019641094518349077)
('E4', 0.045456054586355675)
('F4', 0.025980186840075126)
('F#4', 0.023626704315092523)
('G4', 0.034348100868302756)
('G#4', 0.015188499851936859)
('A4', 0.04013433652614426)
('A#4', 0.019356875506762926)
('B4', 0.019889591721723037)
('C5', 0.019118703300507352)
('C#5', 0.010095943091404973)
('D5', 0.018771837033678209)
('D#5', 0.0078415000842358851)
('E5', 0.014355366448093182)
('F5', 0.0089485811388959908)
('F#5', 0.0065347577216630726)
('G5', 0.0095069355285189033)
('G#5', 0.0045527605475477384)
('A5', 0.0082322945206232557)
('A#5', 0.0053755957724473617)
('B5', 0.0043202201579021927)
('C6', 0.0040672175012402062)
('C#6', 0.0022248089245306001)
('D6', 0.0035526303721295236)
('D#6', 0.00145890868374094)
('E6', 0.0020158685282985109)
('F6', 0.00135404962209706)
('F#6', 0.0008159965904445879)
('G6', 0.0011919069400768813)
('G#6', 0.00049305213512090406)
('A6', 0.00076927933075567772)
('A#6', 0.00042407579073521114)
('B6', 0.00037119035094960204)
('C7', 0.00040256761491976566)
('C#7', 0.00018635949344330502)
('D7', 0.00024479629531594301)
('D#7', 0.00016595086277553192)
('E7', 0.00018979221975798957)
('F7', 0.00012465087430198326)
('F#7', 8.4772249068108674e-05)
('G7', 0.00012014542101395977)
('G#7', 4.2774988061889692e-05)
('A7', 4.1621806565550351e-05)
('A#7', 3.8510898342867464e-05)
('B7', 1.7002722527421984e-05)
('C8', 4.0468625069211004e-05)