code: def triad(note, key):
      
      return [note, intervals.third(note, key), intervals.fifth(note, key)]
docs: Return the triad on note in key as a list.
  
      Examples:
      >>> triad('E', 'C')
      ['E', 'G', 'B']
      >>> triad('E', 'B')
      ['E', 'G#', 'B']