2.03 Melody by Intervals¶
In the previous example the melody was completely random and did not sound like a melody for us. In composed music, the melody often only makes small steps of seconds or thirds. So in this Version the melody is created by intervals. Note duration and rests are set by controlled random.
from pyknon.genmidi import Midi
from pyknon.music import Rest, Note, NoteSeq
import numpy as np
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([-12, -10, -8, -7, -5, -3, -1, 0, 2, 4, 5, 7, 9, 11, 12, 14, 16])
minor = np.array([-12, -10, -9, -7, -5, -4, -2, 0, 2, 3, 5, 7, 8, 10, 12, 14, 15])
var = np.array([1,2,-1])
var2 = np.array([0,2,-1])
var3 = np.array([0,-1,2])
def fade(start,end,steps):
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
tune_L: In this example we are not going to create the melody directly. Instead we control the interval of the next note of the melody. Starting with a second and a third up and downwards and the Perfect unison. The note durations are quarters for the moment.
The size of each interval is created by controlled random. Every interval has an individual probability.
def tune_L():
tune_name = 'tune_L'
np.random.seed(5)
melody_len = 32
scale = major
i_tone_zero = np.argwhere(scale==0)[0]
interval = np.asarray([-2,-1, 0, 1, 2]) # Possible interval
prob_interval = np.asarray([2, 4, 1, 4, 2]) # Probability of each interval
prob_interval = prob_interval/np.sum(prob_interval)
intervals = np.r_[np.random.choice(interval, size=melody_len, p=prob_interval)]
imelody1 = i_tone_zero + np.cumsum(intervals)
melody1 = scale[imelody1]
rythem1 = ran_duration([1/8, 1/4,1/2], [0,2,0], melody_len)
volumes1 = ran_volume([0,100], [0,4], melody_len )
notes1 = NoteSeq( [Note(no+4,octave=5, dur=du, volume=vo) for no,du,vo in zip(melody1,rythem1,volumes1)] )
instruments = [69]
notes = [notes1]
return notes, instruments,tune_name
tune_L
tune_L tune_M: Same as tune_L but with two voices and creating the int_vlt function
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
def tune_M():
tune_name = 'tune_M'
np.random.seed(10)
melody_len = 40
scale = major
i_tone_zero = np.argwhere(scale==0)[0]
melody1 = scale[ i_tone_zero + intvl_melody([-2,-1, 0, 1, 2],[2, 4, 1, 4, 2], melody_len)]
rythem1 = ran_duration([1/8, 1/4,1/2], [1,2,1], melody_len)
volumes1 = ran_volume([0,120], [0,4], melody_len )
melody2 = scale[ i_tone_zero + intvl_melody([-2,-1, 0, 1, 2],[2, 4, 1, 4, 2], melody_len)]
rythem2 = ran_duration([1/8, 1/4,1/2], [1,2,1], melody_len)
volumes2 = ran_volume([0,100], [0,4], melody_len )
notes1 = NoteSeq( [Note(no,octave=6, dur=du, volume=vo) for no,du,vo in zip(melody1,rythem1,volumes1)] )
notes2 = NoteSeq( [Note(no,octave=5, dur=du, volume=vo) for no,du,vo in zip(melody2,rythem2,volumes2)] )
instruments = [110,70]
notes = [notes1,notes2]
return notes, instruments,tune_name
tune_M
tune_M def gen_midi():
# squezze into a MIDI framework
notes, instruments, tune_name = tune_M() # <--- 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
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']) # 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 0 = cut page with 0 pixel
######--- Main ---######
midi_file_name = gen_midi()
midi_play(midi_file_name)
midi_audio(midi_file_name)
midi_png(midi_file_name)