2.07 synchronize voices¶
Till now the voices needed to have the same number of notes to stop at the same time. That means the probability of note lengths had to be the same. The problem with the chord pattern was that the voices could shift and both played in a different chord.
Now the length of the piece is defined by the number of beats. The chord changes are determined by the beat number. The number of notes is now also independent of the piece length.
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
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_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
# currently not in use
def intvl_melody(intvl, prob_intvl, melody_len): #Interval Melody
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
# liniar_range: Generates an range in which the instrument can play.
def liniar_range(r_start, r_top, r_edge, r_end): # 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 )) )
return a_range
# i_last_note: finds de i value of the last not in the actual scale.
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 creats one interval and not an array/melody in one time.
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]
# acceptance: accepts and refuses proposed nots with Metropolis-Hasting Algorythem.
# 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
ran_duration was modified such that the rhythm has the length of melody_len (numbers of beats)
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)
cumsum, melody_len, rythem = 0, melody_len/4 , np.asarray([]) #melody_len/4 as note values are quarter
while cumsum < melody_len:
note_len = np.random.choice(duration, p=prob_duration)
cumsum = cumsum + note_len
rythem = np.append(rythem,note_len)
return rythem , len(rythem)
pattern_gen takes the chord pattern (scales): it repeats the pattern as long the melody is, and generates the beat number where the chords change.
def pattern_gen(scales,melody_len):
scales = np.asarray(scales)
bpb = 4 # beats per bar
factor = int(np.trunc(melody_len/(np.sum(scales[:,0]) * bpb)) + 1) # factor rounded up: how many times is the pattern used
change_times = np.cumsum(np.tile(scales[:,0],factor)) * bpb # create change time list with factor
change_times = np.concatenate((np.asarray([0]),change_times))[:-1] # add 0 at beginig remove last element
for i in range(len(scales)): # send scales to scale_create
scales[i,1] = scale_create(scales[i,1])
pattern = np.tile(scales,(factor,1)) # tile the scales as long the melody is
pattern[:,0] = change_times #insert change_times into scales
pattern = np.delete(pattern, np.argwhere(pattern[:,0] >= melody_len) ,0) # remove unneeded scales
return pattern
acceptance_melody is transformed such that it can read an process the (chord) pattern variable to a melody.
def acceptance_melody(intvl, prob_intvl, pattern, start_note, a_range, notenr, rythem):
melody = np.zeros(notenr, dtype=int)
cum_rythem = np.cumsum(rythem) *4
cum_rythem = np.concatenate(([0],cum_rythem))[:-1] # add 0 at beginig remove last element
scale_change = pattern[:,0]
scale_nr =0
scale = pattern[scale_nr,1]
melody[0] = scale[i_last_note(start_note,scale)]
for npn in range(1, notenr): #npn: note per note (index)
scale_nr = np.ravel(np.argwhere(scale_change <= cum_rythem[npn-1])) [-1]
scale = pattern[scale_nr,1]
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])
#print('npn, len(melody),inote_next,len(scale)', npn, len(melody),inote_next,len(scale))
melody[npn] = scale[inote_next]
return melody
plot_range: plot all ranges together
def plot_range(ranges,labels,title):
fig, ax = plt.subplots()
plt.xlabel('Midi Note')
plt.ylabel('Acceptance')
plt.title(title)
for a_range, lab in zip(ranges,labels):
ax.plot(range(121), a_range,label= lab )
ax.vlines(x=np.linspace(0,108, num=10), ymin=0, ymax=10, color='grey', label='Octaves',linewidth=1) # plot octaves
plt.legend()
plt.show()
tune_S: The voices are now synchronized.
- A different note length distribution is now possible.
- The chord change takes place at the same time in both voices.
def tune_S():
tune_name = 'tune_S'
#np.random.seed(23)
bar, bpb = 13, 4 # bar: Takt , bpb: beat per bar
melody_len = bar * bpb
scales = [[1,CM7],[1,Cm7+9],[1,Cm7+2],[1,C7+7]] #rythem Change
#scales = [[4,C7],[2,C7+5],[2,C7],[1,C7+7],[1,C7+5],[2,C7]] # Blues
pattern = pattern_gen(scales, melody_len)
range_1 = liniar_range(44,51,70,76)
rythem1, notenr_1 = ran_duration([1/8, 1/4,1/2], [2,2,1], melody_len)
melody1 = acceptance_melody([-2,-1, 0, 1, 2],[1, 3, 1, 3, 1],pattern, 60, range_1, notenr_1, rythem1)
volumes1 = ran_volume([0,120], [1,5], notenr_1 )
notes1 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody1,rythem1,volumes1)] )
range_2 = liniar_range(38,41,52,67)
rythem2, notenr_2 = ran_duration([1/8, 1/4,1/2], [4,4,1], melody_len)
melody2 = acceptance_melody([-2,-1, 0, 1, 2],[0, 3, 1, 3, 0],pattern, 46, range_2, notenr_2,rythem2)
volumes2 = ran_volume([0,120], [0,8], notenr_2 )
notes2 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody2,rythem2,volumes2)] )
plot_range([range_1,range_2],['range_1','range_2'],tune_name)
instruments = [66,32]
notes = [notes1,notes2]
return notes, instruments,tune_name
tune_S
tune_S def gen_midi():
# squezze into a MIDI framework
notes, instruments, tune_name = tune_S() # <--- 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.
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
######--- Main ---######
midi_file_name = gen_midi()
midi_play(midi_file_name)
midi_audio(midi_file_name)
midi_png(midi_file_name)
