01
Tempo and rhythm
Tempo and metric modulation, tuplets, polyrhythms, note durations and a metronome.
Our app
Calcophony began as a composer’s own toolkit
In late 2025 Timo Haanpää started writing calculation modules for Jonne Valtonen’s composing work: tempo, rhythm, tuning and spectrum. The collection grew into a complete app for composers and musicians, and its home is calcophony.com.
These modules were originally written for my composition needs, but the program grew so cool that we decided to release the whole thing.
Principal Composer, Valtone Oy
App tour
Thirteen modules in one app
Every module has its own guide with worked examples on calcophony.com.
What it calculates
02
Pitch and tuning
Frequencies, the harmonic series, just-intonation ratios and a strobe tuner.
03
Spectrum
Combination tones, and a spectrogram that finds the implied fundamental.
Continue on calcophony.com
Module guides with worked examples, articles on the arithmetic behind the calculators, and support.