2.04 Scale and Chord Generation
===============================
To create a **scale** or **chord** it is now possible to just define the
notes in one octave. The scale is then generated over the hole midi
range. Only the notes defined in the scale can be played by the melody.
.. code:: python3
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
**scale\_create:** Creates a scale over the hole midi Range from C-2 to
C-7 (midi notes: 0-120). Input is the scale or a chord of one octave.
.. 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])
var = np.array([1,2,-1])
var2 = np.array([0,2,-1])
var3 = np.array([0,-1,2])
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 tones in one octave
tones = np.sort(tones) # sort the tones new
tones = np.unique(tones) # remove duplicate tones
print(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):
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
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
**tune\_O:** Changing the scale creating method.
.. code:: python3
def tune_O():
tune_name = 'tune_O'
np.random.seed(23)
melody_len = 40
scale = scale_create(C7)
i_tone_zero = np.argwhere(scale==60)[0]
melody1 = scale[4+ 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], [1,5], melody_len )
melody2 = scale[ i_tone_zero + intvl_melody([-2,-1, 0, 1, 2],[4, 2, 1, 2, 4], melody_len)]
rythem2 = ran_duration([1/8, 1/4,1/2], [1,2,1], melody_len)
volumes2 = ran_volume([0,100], [1,6], melody_len )
melody3 = scale[-6+ i_tone_zero + intvl_melody([-1, 0, 1],[2, 1, 2], melody_len)]
rythem3 = ran_duration([1/8, 1/4,1/2], [1,2,1], melody_len)
volumes3 = ran_volume([0,100], [0,4], melody_len )
notes1 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody1,rythem1,volumes1)] )
notes2 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody2,rythem2,volumes2)] )
notes3 = NoteSeq( [Note(no,octave=0, dur=du, volume=vo) for no,du,vo in zip(melody3,rythem3,volumes3)] )
instruments = [60,3,32]
notes = [notes1,notes2,notes3]
return notes, instruments,tune_name
.. raw:: html
tune_O
tune_0
.. code:: python3
def gen_midi():
# squezze into a MIDI framework
notes, instruments, tune_name = tune_O() # <--- 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)
tune_0