def from_name(cls, name: str, octave: int = 4) -> "ChordWithRoot":
"""Creates a ChordWithRoot from a name.
`semitones_to_chord_name_options` is used to guess a good name for the chord.
"""
root = None
for letter in LETTERS:
if name.startswith(letter):
root_no_accidental = letter
break
else:
raise InvalidChord(name)
# Very special case: major chord with no accidentals
if len(name) == len(root_no_accidental):
return cls(name, Note(root_no_accidental, octave),
Chord.from_name("major"))
possibly_accidental = name[len(root_no_accidental)]
if possibly_accidental in ACCIDENTALS:
root = Note(root_no_accidental + possibly_accidental, octave)
else:
root = Note(root_no_accidental, octave)
name_without_root = name[len(root.name):]
has_slash = "/" in name_without_root
if has_slash:
name_without_root, bass = name_without_root.split("/")
chord = cls(name, root, Chord.from_name(name_without_root))
chord.chord.add_semitone(-note_diff(bass, root.name))
return chord
else:
return cls(name, root, Chord.from_name(name_without_root))
def from_name(cls, name: str) -> "Chord":
# First determine the octave
octave, name = _separate_octave(name)
if octave is None:
octave = 4
root = None
for letter in LETTERS:
if name.startswith(letter):
root_no_accidental = letter
break
else:
raise InvalidChord(name)
# Very special case: major chord with no accidentals
if len(name) == len(root_no_accidental):
return cls(name, Note(root_no_accidental, octave), Intervals.from_name(""))
possibly_accidental = name[len(root_no_accidental)]
if possibly_accidental in ACCIDENTALS:
root = Note(root_no_accidental + possibly_accidental, octave)
else:
root = Note(root_no_accidental, octave)
name_without_root = name[len(root.name) :]
has_slash = "/" in name_without_root
if has_slash:
name_without_root, bass = name_without_root.split("/")
chord = cls(name, root, Intervals.from_name(name_without_root))
chord.intervals = chord.intervals.add_semitone(-note_diff(bass, root.name))
return chord
else:
return cls(name, root, Intervals.from_name(name_without_root))
def test_github_issue_8_sloppy_midi():
prog = ChordProgression.from_midi_file(
os.path.join(os.path.dirname(__file__), "test_data", "issue_8.mid"))
assert prog == ChordProgression([
Chord(
name="A#min",
root=Note("A#", 3),
intervals=Intervals(name="min", semitones=[0, 3, 7]),
),
Chord(
name="D#",
root=Note("D#", 4),
intervals=Intervals(name="", semitones=[0, 4, 7]),
),
Chord(
name="D#min",
root=Note("D#", 4),
intervals=Intervals(name="min", semitones=[0, 3, 7]),
),
Chord(
name="A#min/G#",
root=Note("G#", 3),
intervals=Intervals(name="min/b7", semitones=[0, 5, 9, 14]),
),
])
def test_github_issue_61_slash_chord_with_octave():
"""https://github.com/jonathangjertsen/jchord/issues/61#issuecomment-777625321"""
chord = Chord.from_name("5C/E")
assert chord == Chord(
name="C/E",
root=Note("C", 5),
intervals=Intervals(name="major", semitones=[-8, 0, 4, 7]),
)
assert chord.bass == Note("E", 4)
def from_root_and_semitones(cls, root: Note, semitones: List[int]) -> "Chord":
chord = Intervals.from_semitones(semitones)
if "/" in chord.name:
chord_name, bass_degree = chord.name.split("/")
new_root = (
Note(root.name, 0).transpose(12 - degree_to_semitone(bass_degree)).name
)
name = f"{new_root}{chord_name}/{root.name}"
else:
name = root.name + chord.name
return cls(name, root, chord)
def test_github_issue_61_progression():
"""https://github.com/jonathangjertsen/jchord/issues/61#issuecomment-777575298"""
prog = ChordProgression.from_string("4F -- 3Am -- 4Dm7 -- 4F --")
assert prog == ChordProgression([
Chord(
name="F",
root=Note("F", 4),
intervals=Intervals(name="major", semitones=[0, 4, 7]),
),
Chord(
name="F",
root=Note("F", 4),
intervals=Intervals(name="major", semitones=[0, 4, 7]),
),
Chord(
name="Am",
root=Note("A", 3),
intervals=Intervals(name="m", semitones=[0, 3, 7]),
),
Chord(
name="Am",
root=Note("A", 3),
intervals=Intervals(name="m", semitones=[0, 3, 7]),
),
Chord(
name="Dm7",
root=Note("D", 4),
intervals=Intervals(name="m7", semitones=[0, 3, 7, 10]),
),
Chord(
name="Dm7",
root=Note("D", 4),
intervals=Intervals(name="m7", semitones=[0, 3, 7, 10]),
),
Chord(
name="F",
root=Note("F", 4),
intervals=Intervals(name="major", semitones=[0, 4, 7]),
),
Chord(
name="F",
root=Note("F", 4),
intervals=Intervals(name="major", semitones=[0, 4, 7]),
),
])
def from_root_and_semitones(cls, root: Note,
semitones: List[int]) -> "ChordWithRoot":
"""Creates a ChordWithRoot from a root `Note` and a list of semitones from the root.
`semitones_to_chord_name_options` is used to guess a good name for the chord.
"""
chord = Chord.from_semitones(None, semitones)
if "/" in chord.name:
chord_name, bass_degree = chord.name.split("/")
new_root = (Note(
root.name,
0).transpose(12 - degree_to_semitone(bass_degree)).name)
name = "{}{}/{}".format(new_root, chord_name, root.name)
else:
name = root.name + chord.name
return cls(name, root, chord)
def midi_to_note(midi: int) -> Note:
"""Returns the `Note` corresponding to the given MIDI note value."""
return Note(CHROMATIC[midi % 12], (midi - 12) // 12)
def test_note_pitch(name, octave, pitch):
assert Note(name, octave).pitch() == pytest.approx(pitch)
def test_transpose_degree(note_in, octave_in, shift, note_out, octave_out):
assert Note(note_in,
octave_in).transpose_degree(shift) == (note_out, octave_out)
def test_note_neq(note, octave, other):
assert Note(note, octave) != other
def test_note_to_midi(note, octave, midi):
assert note_to_midi(Note(note, octave)) == midi
assert midi_to_note(midi) == Note(note, octave)
def test_note_repr(name, octave, the_repr):
assert repr(Note(name, octave)) == the_repr
assert Note(name, octave) == eval(the_repr)
def test_chord_from_root_and_semitone(root, semitones, name):
assert Chord.from_root_and_semitones(Note(root, 4), semitones).name == name
def test_chord_add_root(name_in, octave):
name_then_root = Intervals.from_name(name_in).with_root(Note("A#", octave))
name_and_root = Chord.from_name(f"{octave}A#{name_in}")
assert name_then_root == name_and_root
def test_chord_add_root(name_in, octave):
name_then_root = Chord.from_name(name_in).with_root(Note("A#", octave))
name_and_root = ChordWithRoot.from_name("A#" + name_in, octave=octave)
print(name_and_root._keys())
assert name_then_root == name_and_root
def __init__(self, scale, degrees, root):
self.scale = scale
self.degrees = degrees
self.root = Note(root, octave=4)
assert scale[0] == 0
assert all(degree >= 1 for degree in degrees)
def test_note_eq(sharp, flat, octave):
assert Note(sharp, octave) == Note(flat, octave)
assert Note(flat, octave) == Note(sharp, octave)
def test_note_to_midi_invalid_note():
with pytest.raises(InvalidNote):
note_to_midi(Note("bA", 0))
def test_note_eq_tuple(note, octave):
assert Note(note, octave) == (note, octave)