Bart Massey 2025 (version 0.2.0)

This crate implements functions that take a MIDI key number (in the range 0 to 127 inclusive) and produce a note frequency or period.

There are two versions of these routines: "exact" versions with high precision and "approximate" versions. The approximate versions are "accurate enough". They may be slightly faster, and may take slightly less program memory — neither of these has been tested, though.

The crate can be compiled no_std with --no-default-features. Otherwise the std feature will be used.

Full crate rustdoc is available.

Thanks to Per Gantelius (@stuffmatic on Github) for the microcheby crate. I had previously hand-rolled a similar solution, but theirs was cleaner and better.

This work is made available under the "Apache 2.0 or MIT License". See the file LICENSE.txt in this distribution for license terms.