Markov chain melody generator for Bespoke Synth

markov2.py

# Markov chain riff generator
# (c) Severak 2021
# feed it with notes and it will learn
# feed it with pulses and it will play new notes from those learned

from random import choice

class Markov:
   def __init__(self):
      self.prev = 0
      self.chain = {}
   
   # adds new note to internal memory      
   def add(self, note):
      if self.prev not in self.chain:
         self.chain[self.prev] = []
      self.chain[self.prev].append(note)
      self.prev = note
      
   # generates new note   
   def next(self):
      if self.prev==0:
         raise Exception("Please feed some notes in before generating new ones.")
      if self.prev in self.chain:
         out = choice(self.chain[self.prev])
      else:
         out =  choice(self.chain[0])
      self.prev = out
      return out
      
markov = Markov()

def on_note(n, v):
   markov.add(n)
   me.play_note(n, v)
   
def on_pulse():
   n = markov.next()
   me.play_note(n, 100)