old_contents: 
  from __future__ import print_function
  
  import pynbs
  
  
  my_file = pynbs.read('demo_song.nbs')
  
  print(my_file.header.song_length)
  print(my_file.header.description)
  
  print(my_file.notes)
  print(my_file.layers)
  print(my_file.instruments)
  
  for tick, chord in my_file.song():
      print(tick, [note.key for note in chord])
  
new_contents: 
  from __future__ import print_function
  
  import pynbs
  
  
  # read file
  
  my_file = pynbs.read('demo_song.nbs')
  
  print(my_file.header.song_length)
  print(my_file.header.description)
  
  print(my_file.notes)
  print(my_file.layers)
  print(my_file.instruments)
  
  for tick, chord in my_file.song():
      print(tick, [note.key for note in chord])
  
  
  # new file
  
  new_file = pynbs.blank_file()
  
  
  # edit file
  
  new_file.notes = [
      pynbs.Note(tick=0, layer=0, instrument=0, key=45),
      pynbs.Note(tick=2, layer=0, instrument=0, key=45),
      pynbs.Note(tick=4, layer=0, instrument=0, key=45),
      pynbs.Note(tick=6, layer=0, instrument=0, key=45),
      pynbs.Note(tick=8, layer=0, instrument=0, key=45),
  ]
  
  new_file.header.song_name = 'foo'
  new_file.header.song_author = 'bar'
  new_file.header.blocks_added = 9000
  
  new_file.save('new_file.nbs')
  
subject: Add examples for editing and saving file