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kennethreitz
cceac40a88
New systems:
- Arabic (Maqam): 10 maqamat (ajam, hijaz, nahawand, nikriz, saba, etc.)
with Arabic solfège tone names (Do, Re, Mi, Fa, Sol, La, Si)
- Japanese: 6 pentatonic scales (hirajoshi, in, yo, iwato, kumoi, insen)
and 2 heptatonic scales (ritsu, ryo)
Fretboard improvements:
- Fretboard.guitar() now accepts tuning parameter
- Built-in tunings: standard, drop d, open g, open d, open e, open a,
dadgad, half step down
- Custom tuning via tuple: Fretboard.guitar(("E4", "B3", ...))
- Fretboard.bass(five_string=True) for 5-string bass
Docs:
- Add Musical Systems guide page with all 4 systems
- Add logo to docs
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
143 lines
3.9 KiB
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143 lines
3.9 KiB
ReStructuredText
Musical Systems
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===============
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PyTheory supports four musical systems, each with its own tone names
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and scale patterns.
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Western
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-------
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The standard 12-tone equal temperament system with major/minor scales
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and all seven modes.
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.. code-block:: python
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from pytheory import TonedScale
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c = TonedScale(tonic="C4")
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c["major"].note_names
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# ['C', 'D', 'E', 'F', 'G', 'A', 'B', 'C']
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c["dorian"].note_names
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# ['C', 'D', 'D#', 'F', 'G', 'A', 'A#', 'C']
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**Scales:** major, minor, harmonic minor, ionian, dorian, phrygian,
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lydian, mixolydian, aeolian, locrian, chromatic
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Indian Classical (Hindustani)
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-----------------------------
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The Hindustani system uses **swaras** (Sa, Re, Ga, Ma, Pa, Dha, Ni) and
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organizes scales into **thaats** — the 10 parent scales from which ragas
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are derived.
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.. code-block:: python
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from pytheory import TonedScale
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from pytheory.systems import SYSTEMS
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sa = TonedScale(tonic="Sa4", system=SYSTEMS["indian"])
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sa["bilawal"].note_names # = major scale
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# ['Sa', 'Re', 'Ga', 'Ma', 'Pa', 'Dha', 'Ni', 'Sa']
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sa["bhairav"].note_names # unique to Indian music
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# ['Sa', 'komal Re', 'Ga', 'Ma', 'Pa', 'komal Dha', 'Ni', 'Sa']
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sa["todi"].note_names
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# ['Sa', 'komal Re', 'komal Ga', 'tivra Ma', 'Pa', 'komal Dha', 'Ni', 'Sa']
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**Thaats:** bilawal, khamaj, kafi, asavari, bhairavi, kalyan, bhairav,
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poorvi, marwa, todi
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**Swara notation:**
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- Uppercase = shuddha (natural): Sa, Re, Ga, Ma, Pa, Dha, Ni
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- ``komal`` prefix = flat: komal Re, komal Ga, komal Dha, komal Ni
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- ``tivra`` prefix = sharp: tivra Ma
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Arabic Maqam
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------------
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The Arabic system uses **solfège-based names** (Do, Re, Mi, Fa, Sol, La, Si)
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and organizes scales into **maqamat** (plural of maqam).
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.. note::
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True maqam music uses quarter-tones that cannot be represented in
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12-tone equal temperament. These scales are the closest 12-TET
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approximations.
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.. code-block:: python
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from pytheory import TonedScale
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from pytheory.systems import SYSTEMS
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do = TonedScale(tonic="Do4", system=SYSTEMS["arabic"])
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do["ajam"].note_names # = major scale
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# ['Do', 'Re', 'Mi', 'Fa', 'Sol', 'La', 'Si', 'Do']
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do["hijaz"].note_names # characteristic augmented 2nd
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# ['Do', 'Reb', 'Mi', 'Fa', 'Sol', 'Solb', 'Sib', 'Do']
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do["nikriz"].note_names
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# ['Do', 'Re', 'Mib', 'Fa#', 'Sol', 'La', 'Sib', 'Do']
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**Maqamat:** ajam, nahawand, kurd, hijaz, nikriz, bayati, rast, saba,
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sikah, jiharkah
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Japanese
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--------
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The Japanese system uses Western note names with traditional pentatonic
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and heptatonic scales from Japanese music.
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.. code-block:: python
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from pytheory import TonedScale
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from pytheory.systems import SYSTEMS
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c = TonedScale(tonic="C4", system=SYSTEMS["japanese"])
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c["hirajoshi"].note_names # most iconic Japanese scale
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# ['C', 'D', 'D#', 'G', 'G#', 'C']
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c["in"].note_names # Miyako-bushi, used in koto music
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# ['C', 'C#', 'F', 'G', 'G#', 'C']
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c["yo"].note_names # folk music scale
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# ['C', 'D', 'F', 'G', 'A#', 'C']
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c["ritsu"].note_names # gagaku court music (= Dorian)
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# ['C', 'D', 'D#', 'F', 'G', 'A', 'A#', 'C']
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**Pentatonic scales:** hirajoshi, in, yo, iwato, kumoi, insen
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**Heptatonic scales:** ritsu, ryo
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Cross-System Comparison
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-----------------------
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Since all systems use 12-tone equal temperament, equivalent scales
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produce the same pitches:
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.. code-block:: python
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from pytheory import TonedScale, Tone
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from pytheory.systems import SYSTEMS
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# These are all the same scale with different names
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western = TonedScale(tonic="C4")["major"]
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indian = TonedScale(tonic="Sa4", system=SYSTEMS["indian"])["bilawal"]
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arabic = TonedScale(tonic="Do4", system=SYSTEMS["arabic"])["ajam"]
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# Same pitches
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c4 = Tone.from_string("C4", system="western")
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sa4 = Tone.from_string("Sa4", system="indian")
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do4 = Tone.from_string("Do4", system="arabic")
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c4.frequency # 261.63
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sa4.frequency # 261.63
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do4.frequency # 261.63
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