File size: 5,706 Bytes
c1e08a0
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5e84ffc
 
 
 
 
 
 
 
 
 
b9df2e0
5e84ffc
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
"""Module containing basic music theory concepts and constants."""

from enum import Enum

import numpy as np


class Notes(str, Enum):
    """Enumeration of musical notes in chromatic scale.

    This class represents the twelve notes of the chromatic scale
    and provides methods for note manipulation and validation.
    It inherits from both str and Enum to provide string-like behavior
    while maintaining the benefits of enumeration.

    The str inheritance allows direct string operations on the note values,
    while Enum ensures type safety and provides a defined set of valid notes.

    Examples:
        >>> note = Notes.C
        >>> isinstance(note, str)  # True
        >>> note.lower()  # 'c'
        >>> note + 'm'    # 'Cm'
    """

    C = "C"
    C_SHARP = "C#"
    D = "D"
    D_SHARP = "D#"
    E = "E"
    F = "F"
    F_SHARP = "F#"
    G = "G"
    G_SHARP = "G#"
    A = "A"
    A_SHARP = "A#"
    B = "B"

    @classmethod
    def get_note_index(cls, note: str) -> int:
        """Get the index of a note in the chromatic scale.

        Args:
            note (str): The note name to find the index for.

        Returns:
            int: The index of the note in the chromatic scale (0-11).
        """
        return list(cls).index(cls(note))

    @classmethod
    def get_chromatic_scale(cls, note: str) -> list[str]:
        """Return all notes in chromatic order.

        Args:
            note (str): The note name to start the chromatic scale from.

        Returns:
            list[str]: A list of note names in chromatic order,
                      starting from C (e.g., ["C", "C#", "D", ...]).
        """
        start_idx = cls.get_note_index(note)
        all_notes = [note.value for note in cls]
        return all_notes[start_idx:] + all_notes[:start_idx]

    @classmethod
    def convert_frequency_to_note(cls, frequency: float) -> str:
        """Convert a frequency in Hz to the nearest note name on a piano keyboard.

        Args:
            frequency: The frequency in Hz.

        Returns:
            The name of the nearest note.
        """
        A4_frequency = 440.0
        # Calculate the number of semitones from A4 (440Hz)
        n = 12 * np.log2(frequency / A4_frequency)

        # Round to the nearest semitone
        n = round(n)

        # Calculate octave and index of note name with respect to A4
        octave = 4 + (n + 9) // 12
        note_idx = (n + 9) % 12

        note = cls.get_chromatic_scale(cls.C)[note_idx]
        return f"{note}{octave}"

    @classmethod
    def convert_frequency_to_base_note(cls, frequency: float) -> str:
        """Convert frequency to base note name without octave number.

        Args:
            frequency: Frequency in Hz

        Returns:
            Base note name (e.g., 'C', 'C#', 'D')
        """
        note_with_octave = cls.convert_frequency_to_note(frequency)
        return note_with_octave[:-1]  # Remove the octave number


class Scale:
    """Musical scale representation and operations.

    This class handles scale-related operations including scale generation
    and scale note calculations.
    """

    SCALES = {
        "major": [0, 2, 4, 5, 7, 9, 11],
        "natural_minor": [0, 2, 3, 5, 7, 8, 10],
        "harmonic_minor": [0, 2, 3, 5, 7, 8, 11],
        "diminished": [0, 2, 3, 5, 6, 8, 9, 11],
    }

    @classmethod
    def get_scale_notes(cls, root_note: str, scale_type: str) -> list[str]:
        """Generate scale notes from root note and scale type.

        Args:
            root_note: The root note of the scale.
            scale_type: The type of scale (e.g., "major", "natural_minor").

        Returns:
            A list of note names in the scale.

        Raises:
            ValueError: If root_note is invalid or scale_type is not recognized.
        """
        if scale_type not in cls.SCALES:
            raise ValueError(f"Invalid scale type: {scale_type}")

        scale_pattern = cls.SCALES[scale_type]
        chromatic = Notes.get_chromatic_scale(root_note)
        return [chromatic[interval % 12] for interval in scale_pattern]


class ChordTone:
    """Musical chord tone representation and operations.

    This class handles chord tone-related operations
    including chord tone generation and chord tone calculation.
    """

    CHORD_TONES = {
        "maj": [0, 4, 7, 9],
        "maj7": [0, 4, 7, 11],
        "min7": [0, 3, 7, 10],
        "min7(b5)": [0, 3, 6, 10],
        "dom7": [0, 4, 7, 10],
        "dim7": [0, 3, 6, 9],
    }

    @classmethod
    def get_chord_tones(cls, root_note: str, chord_type: str) -> list[str]:
        """Generate chord tones from root note and chord type.

        Args:
            root_note: The root note of the chord.
            chord_type: The type of chord (e.g., "maj", "maj7").

        Returns:
            A list of note names in the chord.
        """
        if chord_type not in cls.CHORD_TONES:
            raise ValueError(f"Invalid chord type: {chord_type}")

        chord_pattern = cls.CHORD_TONES[chord_type]
        chromatic = Notes.get_chromatic_scale(root_note)
        return [chromatic[interval] for interval in chord_pattern]


class Intervals:
    """Musical interval representation and operations.

    This class handles interval-related operations
    including interval generation and interval calculation.
    """

    INTERVALS_MAP = {
        "perfect 1st": 0,
        "minor 2nd": 1,
        "major 2nd": 2,
        "minor 3rd": 3,
        "major 3rd": 4,
        "perfect 4th": 5,
        "diminished 5th": 6,
        "perfect 5th": 7,
        "minor 6th": 8,
        "major 6th": 9,
        "minor 7th": 10,
        "major 7th": 11,
    }