Calcophony
The Composer's Calculator
Free · In‑App Purchases · Designed for iPad
Extended launch offer: 50% off the one-time full unlock. Get every Calcophony module permanently, with no subscription.
Calcophony is a scientific calculator for composers and musicians. It handles the mathematical side of music composition, from tempo and metric modulation to tuning systems, just-intonation ratios, polyrhythms, spectral analysis, and spectrograms, plus a metronome and a chromatic, instrument-aware tuner.
TEMPO MODULATION CALCULATOR
Enter a starting tempo to compare note-value reinterpretations in a BPM matrix, with near-integer results highlighted. Adjust tolerance, tuplet complexity, and target-BPM matching.
METRIC MODULATION PLANNER
Bridge distant tempos in multiple steps, with optional ordered intermediate tempos and pivot note values at each transition. Compare paths and target deviations, with closest alternatives when no path meets your tolerance. Adjust maximum steps and tuplet complexity.
RHYTHM & SUBDIVISION CALCULATOR
Calculate tuplets and nested groupings, with per-note durations in milliseconds, total duration, and equivalent note-value groupings.
POLYRHYTHM VISUALIZER
Audition two or more pulse streams over a base tempo. See attack points, coincidences, and numbered composite patterns. Choose nested polygons, polygons on one circle, or rings. Mute or solo streams with distinct click timbres.
FREQUENCY & PITCH CONVERTER
Convert between Hz, pitch name, MIDI note number, and cents. Set your reference pitch and audition the current pitch.
HARMONIC SERIES EXPLORER
Explore harmonic or subharmonic series from any fundamental. See each partial's frequency, nearest pitch, and cents. Highlight interval and chord families, audition one or many partials, and play them from a grand staff.
INTERVAL & TUNING CALCULATOR
Enter an interval by name, ratio, or cents. Approximate cents values with just-intonation ratios under a selectable prime limit, up to 31. Compare 12-TET neighbors and cents deviations. Set a root pitch to see beat frequency.
RATIO CALCULATOR
Multiply, divide, and raise just-intonation ratios to powers using exact arithmetic. See simplified fractions in full register and octave-reduced, with decimal and cents values. Audition intervals together or in sequence. Stack twelve fifths to reveal the Pythagorean comma.
SPECTRAL CALCULATOR
Compute sum, difference, Tartini, and second-order combination tones. See reinforced tones and implied bass fundamentals whose harmonic series fits your inputs.
SPECTROGRAM ANALYZER
Import audio or record from the microphone, then explore its frequency content with pinch-to-zoom and pan. Select a time to inspect partials, audition them from a grand staff, and find the implied fundamental. Share analysis as plain text.
DURATION CALCULATOR
Generate note-value duration tables in milliseconds and MM:SS.mmm, with an optional offset for scoring and session work. Enter a duration to solve for tempo or find the closest standard note value.
METRONOME
Sample-accurate timing, common and asymmetric meters, ten sound sets and a silent mode, custom accents, subdivision clicks, tap tempo, count-in, and tempo ramping. Share your setup as plain text.
TUNER
Detect pitches down to A0, with presets for guitar, bass, violin, viola, cello, double bass, ukulele, mandolin, and banjo. Choose alternate tunings including Drop D, DADGAD, and Open G. Switch between meter and strobe views and adjust tolerance. Explore Werckmeister III, Kirnberger III, Vallotti, Young I, quarter-comma meantone, and Pythagorean temperaments. Set reference A4, play per-string reference tones, and transpose instrument tunings by semitones. Share settings and readings as plain text.
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Free tier includes Tempo Modulation, Frequency & Pitch, and the Metronome. A 7-day free trial unlocks every module. A single one-time purchase unlocks everything permanently, with no subscriptions.
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Version 1.0.4 improves how the app plays sound.
IMPROVED
- Metronome, Polyrhythm, and the rhythm calculators' loop and reference click use the improved audio-thread timing.
- Tone and interval playback in Frequency & Pitch, Interval & Tuning, Ratio Calculator, the Tuner reference tones, and Spectrogram file playback now all use the same engine.
- Interval audition: in melodic mode, the base tone and interval tone are evenly spaced.
- Tap tempo registers the moment of each touch now more accurately, so the BPM follows taps more closely.
- Updated the underlying app framework.
FIXED
- A phone call, Siri, or another app taking over audio now stops playback cleanly. The Tuner turns its microphone off after an interruption; tap the mic button to resume.
REMOVED
- The "Scheduler lookahead" slider in Metronome options. The new engine does not need it.
Questions or problems: support@calcophony.com
The developer, Valtone Oy, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Location
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Valtone Oy
- Size
- 69.3 MB
- Category
- Music
- Compatibility
Requires iOS 16.4 or later.
- iPhone
Requires iOS 16.4 or later. - iPad
Requires iPadOS 16.4 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Calcophony Pro $4.99
- Copyright
- © 2026 Valtone Oy