1class Tone():
  2    TONES = ('C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B')
  3
  4    def __init__(self,string):
  5        self.string = string
  6
  7    def __str__(self):
  8        return self.string
  9    
 10    def __eq__(self, other):
 11        if isinstance(other, Tone):
 12           return  self.string == other.string
 13        return False
 14        
 15    def __hash__(self):
 16        return hash(self.string)
 17    
 18    def __add__(self, other):
 19        if isinstance(other, Tone):
 20            return Chord(self, other)
 21        elif isinstance(other, Interval):   
 22            new_index = Tone.TONES.index(self.string)
 23            new_index += other.number_of_semitones
 24            new_chord = Tone.TONES[new_index % 12]
 25            return Tone(new_chord)
 26        
 27    def __radd__(self, other):
 28        if isinstance(other, Tone):
 29            return other.__add__(self)
 30        elif isinstance(other, Chord):
 31            return other.__add__(self)
 32        else: 
 33            raise TypeError("Invalid operation")
 34
 35    def __sub__(self, other):
 36        if isinstance(other, Tone):
 37            self_index = Tone.TONES.index(self.string)
 38            other_index = Tone.TONES.index(other.string)
 39            return Interval((self_index - other_index) % 12)
 40        
 41        elif isinstance(other, Interval):   
 42            new_index = Tone.TONES.index(self.string)
 43            new_index -= other.number_of_semitones
 44            new_chord = Tone.TONES[new_index % 12]
 45            return Tone(new_chord)
 46        
 47    def __rsub__(self, other):
 48        if isinstance(other, Tone):
 49            return other.__sub__(self)
 50        raise TypeError("Invalid operation")
 51        
 52
 53class Interval():
 54    INTERVALS = ( 
 55        "unison", "minor 2nd", "major 2nd", "minor 3rd",
 56        "major 3rd", "perfect 4th", "diminished 5th",
 57        "perfect 5th", "minor 6th", "major 6th",
 58        "minor 7th", "major 7th"
 59    )
 60
 61    def __init__(self, integer):
 62        self.number_of_semitones = integer % 12
 63
 64    def __str__(self):
 65        return self.INTERVALS[self.number_of_semitones]
 66    
 67    def __add__(self, other):
 68        if isinstance(other, Interval):
 69            new_interval = (self.number_of_semitones + other.number_of_semitones) % 12
 70            return Interval(new_interval)
 71        
 72    def __neg__(self):
 73        return Interval(-self.number_of_semitones)
 74
 75class Chord():
 76    def __init__(self, root, *args): 
 77
 78        self.root = root
 79        self.all_given_tones = [root]
 80
 81        for i in args:
 82           self.all_given_tones.append(i)
 83
 84        self.unique_tones = set(self.all_given_tones)
 85
 86        if len(self.unique_tones) < 2:
 87            raise TypeError("Cannot have a chord made of only 1 unique tone")
 88        
 89        
 90    def __str__(self):
 91        root_index = Tone.TONES.index(self.root.string)
 92        sorted_tones = sorted(
 93            self.unique_tones,
 94            key=lambda tone: (Tone.TONES.index(tone.string) - root_index) % 12
 95        )
 96
 97        return "-".join(tone.string for tone in sorted_tones)
 98    
 99    def is_minor(self):
100        return any([abs(Tone.TONES.index(tone.string) - Tone.TONES.index(self.root.string)) == 3 for tone in self.unique_tones])
101    
102    def is_major(self):
103        return any([abs(Tone.TONES.index(tone.string) - Tone.TONES.index(self.root.string)) == 4 for tone in self.unique_tones])
104    
105    def is_power_chord(self):
106        return not self.is_minor() and not self.is_major()
107    
108    def __add__(self, other):
109        if isinstance(other, Tone):
110            new_tones = [tone for tone in self.unique_tones] + [other]
111            return Chord(self.root, *new_tones)
112        elif isinstance(other, Chord):
113            new_tones = [tone for tone in self.unique_tones] +  [tone for tone in other.unique_tones]
114            return Chord(self.root, *new_tones)
115
116        
117    def __sub__(self, other):
118          if isinstance(other, Tone):
119            if other not in self.unique_tones:
120                raise TypeError (f'Cannot remove tone {other} from chord {self}')
121            else:
122                new_tones = [tone for tone in self.unique_tones if tone != other]
123                return Chord(self.root, *new_tones)
124
125    def transposed(self, interval):
126        if isinstance(interval, Interval):
127            transposed_tones = [tone + interval for tone in self.unique_tones if tone != self.root]
128            self.root += interval 
129            return Chord(self.root, *transposed_tones)