code: def save_string_and_execute_LilyPond(ly_string, filename, command):
      
      ly_string = '\\version "2.10.33"\n' + ly_string
      if filename[-4:] in ['.pdf', '.png']:
          filename = filename[:-4]
      try:
          f = open(filename + '.ly', 'w')
          f.write(ly_string)
          f.close()
      except:
          return False
      command = 'lilypond %s -o "%s" "%s.ly"' % (command, filename, filename)
      print 'Executing: %s' % command
      p = subprocess.Popen(command, shell=True).wait()
      os.remove(filename + '.ly')
      return True
docs: A helper function for to_png and to_pdf. Should not be used directly.