2.06 Chord Change
=================
Now a chord model can be defined manually instead of one single scale.
The Chord pattern is repeated. The chords change after six notes.
The chord changes gets improved in the version 2.07 2.08 and 2.10
.. code:: python3
from pyknon.genmidi import Midi
from pyknon.music import Rest, Note, NoteSeq
import numpy as np
import matplotlib.pyplot as plt
**Instruments:** Available are at lest the 128 General-Midi (GM)
Instruments. Depending on the sound-fonts there is a bigger choice. A
list of the GM instruments can be found here.
https://jazz-soft.net/demo/GeneralMidi.html
.. code:: python3
major = np.array([ 0, 2, 4, 5, 7, 9, 11])
minor = np.array([ 0, 2, 3, 5, 7, 8, 10])
C7 = np.array([ 0, 4, 7, 10])
CM7 = np.array([ 0, 4, 7, 11])
Cm7 = np.array([ 0, 3, 7, 10])
Cm = np.array([ 0, 3, 7])
C = np.array([ 0, 4, 7])
bass= np.array([ 0])
def scale_create(tones):
tones = np.asarray(tones) # tones which form chord or scale in the first octave (0-11)
if any(tones > 11): # tones over one octave?
tones = np.mod(tones,12) # set the thones in one octave
tones = np.sort(tones) # sort the tones new
tones = np.unique(tones) # remove duplicate tones
octave = np.repeat( np.linspace(0,108, num=10), len(tones))
scale = np.add( octave, np.tile(tones, 10)) # add element wise octave and note
return scale.astype(int)
def fade(start,end,steps): # currently not in use
fade = np.around( np.linspace(start,end,num=steps))
fade = fade.astype(int)
return fade
def ran_duration(duration, prob_duration, melody_len):
duration= np.asarray(duration) # this are the allowed durations of the notes
prob_duration = np.asarray(prob_duration) # this are the probabilities how often each will occure
prob_duration = prob_duration/np.sum(prob_duration)
rythem = np.r_[np.random.choice(duration, size=melody_len, p=prob_duration)]
return rythem
def ran_volume(volume, prob_volume, melody_len):
volume = np.asarray(volume, dtype=int) # this are the allowed volumes of thenotes
prob_volume = np.asarray(prob_volume) # this are the probabilities how often each volume will occure
prob_volume = prob_volume/np.sum(prob_volume)
volumes = np.r_[np.random.choice(volume, size=melody_len, p=prob_volume)]
return volumes
def intvl_melody(intvl, prob_intvl, melody_len): #Interval Melody # currently not in use
intvl = np.asarray(intvl) # Possible interval
prob_intvl = np.asarray(prob_intvl) # Probability of each interval
prob_intvl = prob_intvl/np.sum(prob_intvl)
intervals = np.r_[np.random.choice(intvl, size=melody_len, p=prob_intvl)]
imelody = np.cumsum(intervals)
return imelody
**linear\_range:** Generates an range in which the instrument can play.
.. code:: python3
def liniar_range(r_start, r_top, r_edge, r_end, title): # acceptance range of the instrument
h = 100 # hight of acceptance function
a_range = np.zeros(121, dtype=int) # only to midi =120 as 127 is not a complete octave
np.put(a_range, range(r_start,r_top), np.linspace(0,h, num=(r_top -r_start)) )
np.put(a_range, range(r_top, r_edge), np.linspace(h,h, num=(r_edge-r_top )) )
np.put(a_range, range(r_edge, r_end), np.linspace(h,0, num=(r_end -r_edge )) )
fig, ax = plt.subplots()
ax.plot(range(121), a_range)
plt.title(str(title)+': '+str([r_start, r_top, r_edge, r_end]))
plt.show()
return a_range
**i\_last\_note:** finds the i value of the last note in the actual
scale.
.. code:: python3
def i_last_note(note, scale):
i_note = (np.abs(scale - note)).argmin()
return i_note
**intvl\_next** is a modification of intvl\_melody. But it does only
creates **one** interval and not an array/melody in one time.
.. code:: python3
def intvl_next(intvl, prob_intvl): #singel interval
intvl = np.asarray(intvl) # Possible interval
prob_intvl = np.asarray(prob_intvl) # Probability of each interval
prob_intvl = prob_intvl/np.sum(prob_intvl)
interval = np.random.choice(intvl, size=1, p=prob_intvl)
return interval[0]
.. code:: python3
# x is the value in the aceptance range of the current note, while x_new is it from the proposoal note
def acceptance(x, x_new):
if x_new < 1:
if x < 1:
print('start_note not in range')
return
quot = x_new/x
if quot >= 1: return True
if np.random.uniform(0,1)< quot: return True
else: return False
.. code:: python3
def acceptance_melody(intvl, prob_intvl, scales, start_note, a_range, melody_len):
melody = np.zeros(melody_len, dtype=int)
melody[0] = scales[0][i_last_note(start_note,scales[0])]
scale_nr =0
for npn in range(1, melody_len):
# -- scale changing ------
if np.mod(npn,6)==0: # number in mp.mod: how many tones in one scale
scale_nr = scale_nr + 1
if scale_nr >= len(scales):
scale_nr =0
scale = scales[scale_nr]
accept = False
while not accept: # aslong acept == False
inote = i_last_note(melody[npn-1],scale)
inote_next = inote + intvl_next(intvl, prob_intvl) # add current not with Proposition
accept_val = a_range[[melody[(npn-1)],scale[inote_next]]] # get acceptance values
accept = acceptance(accept_val[0],accept_val[1])
melody[npn] = scale[inote_next]
return melody
**tune\_Q:** \|I\|VI\|II\|V\| scheme
.. code:: python3
def tune_Q():
tune_name = 'tune_Q'
#np.random.seed(23)
melody_len = 60
#scales = [scale_create(major),scale_create(minor)]
scales = [scale_create(C),scale_create(Cm +9),scale_create(Cm+2),scale_create(C7+7)] # I|VI|II|V|
range_1 = liniar_range(55,65,80,93,'Range 1')
melody1 = acceptance_melody([-2,-1, 0, 1, 2],[1, 3, 1, 3, 1],scales, 67, range_1, melody_len)
rythem1 = ran_duration([1/8, 1/4,1/2], [3,2,1], melody_len)
volumes1 = ran_volume([0,120], [0,8], melody_len )
notes1 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody1,rythem1,volumes1)] )
instruments = [68]
notes = [notes1]
return notes, instruments,tune_name
.. raw:: html
tune_Q
tune_Q
**tune\_R:** Blues scheme with two voices.
As the melody creating is independent for each voice, the chord changes
is not simultaneously. This needs to be corrected.
.. code:: python3
def tune_R():
tune_name = 'tune_R'
#np.random.seed(23)
melody_len = 60
#scales = [scale_create(C),scale_create(Cm +9),scale_create(Cm+2),scale_create(C7+7)] # I|VI|II|V|
#scales = [scale_create(major),scale_create(minor)]
#scales = [scale_create(CM7),scale_create(Cm7+9),scale_create(Cm7+2),scale_create(C7+7)] #rythem Change
scales = [scale_create(C7),scale_create(C7+5),scale_create(C7),scale_create(C7+7),scale_create(C7+5),scale_create(C7)] # Blues
range_1 = liniar_range(30,48,72,84, tune_name +' Range 1')
melody1 = acceptance_melody([-2,-1, 0, 1, 2],[1, 3, 1, 3, 1],scales, 60, range_1, melody_len)
rythem1 = ran_duration([1/8, 1/4,1/2], [4,2,1], melody_len)
volumes1 = ran_volume([0,120], [2,8], melody_len )
notes1 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody1,rythem1,volumes1)] )
range_2 = liniar_range(38,43,55,67,tune_name+ ' Range 2')
melody2 = acceptance_melody([-2,-1, 0, 1, 2],[0, 3, 1, 3, 0],scales, 46, range_2, melody_len)
rythem2 = ran_duration([1/8, 1/4,1/2], [4,2,1], melody_len)
volumes2 = ran_volume([0,120], [0,8], melody_len )
notes2 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody2,rythem2,volumes2)] )
instruments = [0,33]
notes = [notes1,notes2]
return notes, instruments,tune_name
.. raw:: html
tune_R
tune_R
.. code:: python3
def gen_midi():
# squezze into a MIDI framework
notes, instruments, tune_name = tune_R() # <--- select a tune <<-- <<<<<<<<<--- select a tune -----
nTracks = len(notes)
m = Midi(number_tracks=nTracks, tempo=120, instrument=instruments)
for iTrack in range(nTracks):
m.seq_notes(notes[iTrack], track=iTrack)
#--- write the MIDI file -----
midi_file_name = tune_name +'.mid' # set the name of the file
m.write(midi_file_name)
return midi_file_name
Midi: Play and Generate audio-file
----------------------------------
External players offered a better sound quality in comparison with
python libraries. We use **VLC** and **Musescore**. The **soundfont**
for the VLC player is defined over the command line. For Musescore
through the Gui in the preferences.
.. code:: python3
import subprocess
default_soundfont = '/usr/share/sounds/sf3/MuseScore_General.sf3'
def midi_play(midi_in, soundfont= default_soundfont):
subprocess.call(['cvlc', midi_in , 'vlc://quit', '--soundfont', '/home/viturin/-vitis/Documents/MuseScore2/Soundfonts/Compifont_13082016.sf2']) # cvlc = vlc without gui
def midi_audio(midi_in, name_out = 'none', soundfont= default_soundfont):
if name_out == 'none' :
name_out = midi_in.replace('.mid', '.flac')
else:
name_out = name_out + '.flac'
subprocess.call(['mscore', '-o', name_out, midi_in]) # -o = export as
def midi_png(midi_in, name_out = 'none'):
if name_out == 'none' :
name_out = midi_in.replace('.mid', '.png')
else:
name_out = name_out + '.png'
subprocess.call(['mscore', '-o', name_out, '-T', '2', midi_in]) # -o = export as , -T 2 = cut page with 2 pixel
.. code:: python3
######--- Main ---######
midi_file_name = gen_midi()
midi_play(midi_file_name)
midi_audio(midi_file_name)
midi_png(midi_file_name)
.. image:: output_21_0.png
.. image:: output_21_1.png
tune_Q 
tune_R