Calcophony
A scientific calculator for composers.
Calculate tempo ratios, tuplet subdivisions, overtone frequencies, and metric modulation paths without manual transcription or a spreadsheet. Calcophony keeps these workflows together and preserves exact results until display.
Free to download, with a 7-day trial of every Pro module. iPhone, iPad, and Apple Silicon Mac.
Modules
Tempo & Rhythm
Tempo Modulation Free
All tempo relationships from a source BPM. Explore every possible modulation from a given starting point in a matrix view, with tuplet complexity controls and configurable precision.
Metric Modulation
Plan multi-step modulations between distant tempos. Discover ordered chains of modulation steps with pivot note values, final deviation, and transition duration.
Rhythm & Subdivision
Work out complex rhythmic relationships. Get exact durations, click-track pulses, and equivalent groupings for nested tuplets and polyrhythms.
Duration Calculator
Generate a full table of note-value durations at any tempo, with milliseconds, MM:SS.mmm elapsed-time output, and optional time offset.
Metronome Free
Create metronomes with custom time signatures, configurable sound sets, accent patterns, tempo ramps, and asymmetric meter support.
Polyrhythm Visualizer
Visualize composite rhythms with an interactive circular display. Configure up to 8 independent streams, find coincidence points, and audition the composite pattern with playback controls.
Pitch & Frequency
Frequency & Pitch Free
Bidirectional Hz, pitch name, cents, and MIDI conversion. Includes exact cents deviation and customizable reference pitch (e.g., A4 = 440 Hz).
Harmonic Series
Visualize and audition the overtone series. Compare exact Hz to nearest 12-TET pitch with cents deviation, and play back individual partials.
Tuner
High-precision chromatic and instrument-aware pitch detection with strobe display. Supports built-in instrument tunings, historical temperaments, and reference tone playback.
Interval & Tuning
Convert intervals between names, ratios, and cents; compare off-grid inputs against both bracketing 12-TET semitones; and find constrained just-intonation ratios for cents input.
Ratio Calculator
Multiply, divide, and stack just-intonation ratios into a single result. Chain ratios with exponents, see the octave-reduced fraction with its decimal and cents value, and audition the interval against a 1/1 base tone.
Spectral Calculator
Compute combination tones (sum, difference, Tartini, and second-order products) for any set of input frequencies. Identify which results sit near harmonics of an input and audition each tone directly.
Spectrogram Analyzer
Load or record audio and watch its frequencies unfold over time as a zoomable heatmap, or as peak trails tracing the loudest partials. Tap any moment to read those partials, their harmonic ratios, and the implied fundamental.
Under the Hood
True Strobe Simulation
A native GPU module renders the real-time strobe disc simulation. The disc rotation responds directly to measured phase, the same way a mechanical strobe tuner does.
Exact Arithmetic
Musical ratios use exact fractional arithmetic where precision matters. Results stay exact until final display.
All On-Device
Core calculations run locally. Calculator workflows work offline without an account or required telemetry.
Pricing
Free
$0
- Tempo Modulation
- Frequency & Pitch
- Metronome
- 7-day free trial of all modules
Pro
$9.99one-time
- All modules unlocked
- Future modules included
- Try free for 7 days
- No subscription
Schools & institutions: contact us about classroom and multi-device pricing.