2.02 Random Melody
==================

The Melody plays completely random in a range bit more than two octaves.
Note duration and rests are set by controlled random.

.. 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://en.wikipedia.org/wiki/General\_MIDI#Program\_change\_events
Remember to subtract 1, as the list starts with 1 and not 0.

.. code:: python3

    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\_K:** Creating a track with complete random melody and controlled
random rhythm

.. code:: python3

    def tune_K():
        tune_name = 'tune_K'  # Complete random melody
        np.random.seed(12)
        melody_len = 20
        imelody1 = np.random.randint(len(minor), size=melody_len) # creat melody in index form
        melody1 = minor[imelody1]
        
        imelody2 = np.random.randint(len(minor), size=melody_len) # creat melody in index form
        melody2 = minor[imelody2]
        
        rythem1 = ran_duration([1/8, 1/4,1/2], [4,2,1], melody_len)
        rythem2 = ran_duration([1/8, 1/4,1/2], [4,2,1], melody_len)
        volumes1 = ran_volume([0,100], [1,4], melody_len )
        volumes2 = ran_volume([0,120], [1,4], melody_len )
    
        notes1 = NoteSeq( [Note(no+4,octave=5, dur=du, volume=vo) for no,du,vo in zip(melody1,rythem1,volumes1)] )
        notes2 = NoteSeq( [Note(no-8,octave=5, dur=du, volume=vo) for no,du,vo in zip(melody2,rythem2,volumes2)] )
        instruments = [45,68]
        notes = [notes1, notes2]
        return notes, instruments,tune_name

.. raw:: html

    <br><audio controls="controls" src="https://raw.githubusercontent.com/schuhva/Music-Generation/master/doc/releases/2.02/tune_K.flac" type="audio/flac"></audio>
     tune_K     
     
     <br><img src="https://raw.githubusercontent.com/schuhva/Music-Generation/master/doc/releases/2.02/tune_K-1.png">
     tune_K  <br><br><br>

.. code:: python3

    
    def gen_midi():
    #     squezze into a MIDI framework
        notes, instruments, tune_name = tune_K() #  <--- 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**

.. 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'])   # 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

.. code:: python3

    ######---  Main  ---######
    midi_file_name = gen_midi()
    
    midi_play(midi_file_name)
    midi_audio(midi_file_name)
    midi_png(midi_file_name)