code: def get_chords_histogram_norm(chords, key):
      key_index = circle_of_fifth.index(key)
  
      chords_histogram = [0] * 24
      if len(chords) > 0:
          for chord in chords:
              chord_index = circle_of_fifth.index(chord) - key_index
              if chord_index < 0:
                  chord_index += len(circle_of_fifth)
              chords_histogram[chord_index] += 1
  
          for i in range(len(chords_histogram)):
              chords_histogram[i] *= 100.0 / len(chords)
  
      return chords_histogram
  
imports: import essentia
  from essentia import EssentiaError, INFO
label_desc: Use image node_id 1 for calling a global function with example usage: get_chords_histogram_norm(chords, key) and returns: chords_histogram