octarver 0.1.4

Octave Range Converter - Convert between musical note names and frequencies

Octarver

Octave Range Converter

A lightweight command-line tool for converting between musical note names and frequencies across octave ranges.

Why Octarver?

While libraries like librosa provide note-frequency conversion functions, Octarver is designed specifically as a lightweight CLI tool for quick conversions:

• Lightweight: No heavy dependencies (unlike librosa's 100MB+ install)
• Fast: Instant command-line results without writing Python code
• Simple: Purpose-built for one task, does it well
• Portable: Easy to use in shell scripts and workflows

Perfect for musicians, audio engineers, and students who need quick frequency-note conversions without importing a full audio analysis library.

Features

• Convert frequency (Hz) to note name (e.g., 440 → A4)
• Convert note name to frequency (e.g., A4 → 440Hz)
• Supports octave specification (O1-O8)
• Based on equal temperament with A4 = 440Hz

Installation

pip install octarver

Or install from source:

git clone https://github.com/tkuro11/octarver.git
cd octarver
pip install -e .

Usage

usage: octarver [-h] [-o OCTAVE] [-n NOTE] [-f FREQ] [note_spec ...]

convert between the note name and frequency

positional arguments:
  note_spec             specify the octave and the note or frequency. 
                        Examples: 'O3A', 'C#', '440'
                        The octave can be omitted (default O4).

options:
  -h, --help            show this help message and exit
  -o OCTAVE, --octave OCTAVE
                        set the octave (this takes precedence)
  -n NOTE, --note NOTE  set the note (this takes precedence)
  -f FREQ, --freq FREQ  set frequency (this takes precedence)

Examples

Frequency to Note

$ octarver 440
A4: 440.00 Hz

$ octarver 523.25
C5: 523.25 Hz

$ octarver 880
A5: 880.00 Hz

Note to Frequency

$ octarver A4
A4: 440.00 Hz

$ octarver O5C
C5: 523.25 Hz

$ octarver C#
C#4: 277.18 Hz

$ octarver O3G#
G#3: 207.65 Hz

Using Options

$ octarver -o 5 -n C
C5: 523.25 Hz

$ octarver -f 440
A4: 440.00 Hz

Technical Details

• Tuning Standard: A4 = 440Hz (ISO 16:1975)
• Temperament: 12-tone equal temperament
• Frequency Range: Supports octaves O1 through O8
• Formula: f = 440 × 2^((n-49)/12), where n is the number of semitones from A4

Roadmap

✅ v0.1.x (Current)

Simple, lightweight frequency-note converter with A4=440Hz and 12-tone equal temperament.

🔲 v0.2.x (Next Major Release)

Alternative Tunings - Add support for:

• Custom A4 reference frequencies
  • A4 = 442Hz (Modern orchestral pitch, common in Europe)
  • A4 = 415Hz (Baroque pitch for historical performance)
  • A4 = 432Hz (Alternative tuning)
  • A4 = 435Hz (French standard, 1859)
• Historical and alternative tuning systems (Just intonation, Pythagorean, etc.)
• Integration with pitchtools
• Optional advanced features: pip install octarver[advanced]

🔲 v0.3.x (Future)

Enhanced Features - Additional functionality:

• MIDI note number conversion
• Cent deviation display for tuning accuracy
• Batch processing from files
• Multiple output formats (JSON, CSV)

💡 Ideas Under Consideration

• Interactive REPL mode for quick conversions
• Harmonic series calculations
• Chord frequency analysis

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Note: The roadmap is subject to change based on user feedback and feature requests. Please open an issue if you have suggestions!

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License

Author

tkuro11

Links

• Repository: https://github.com/tkuro11/octarver
• Issues: https://github.com/tkuro11/octarver/issues
• PyPI: https://pypi.org/project/octarver/ (coming soon)