Make xenharmonic music and explore musical tunings.

Resources

Overview

microwave is a microtonal modular waveform synthesizer with soundfont rendering capabilities based on:

It features a virtual piano UI enabling you to play polyphonic microtonal melodies with your touch screen, computer keyboard, MIDI keyboard or mouse. The UI provides information about pitches and just intervals in custom tuning systems.

The built-in modular synthesis engine does not use any fixed architecture and can be customized to react to all sorts of input events.

Demo

Download / Installation

Option A: Try out the web app to get a very first impression:

Option B: Download a precompiled version of microwave for the supported target architectures:

Option C: Use Cargo to build a fresh binary from scratch for your own target architecture:

```bash

If you are using Linux: Make sure all dev dependencies are installed.

On the CI environment (Ubuntu 20.04) we only need to add one library:

sudo apt install libasound2-dev

Make sure pkg-config is installed

sudo apt install pkg-config

cargo install -f microwave ```

microwave should run out-of-the box on a recent (Ubuntu) Linux, Windows or macOS installation. If it doesn't, the problem is probably caused by the Nannou framework. In that case, try following these instructions.

Usage

Hint: Run microwave with parameters from a shell environment (Bash, PowerShell). Double-clicking on the executable will not provide access to all features!

bash microwave run # 12-EDO scale (default) microwave run steps 1:22:2 # 22-EDO scale microwave run scl-file my_scale.scl # imported scale microwave run help # Print help about how to set the parameters to start microwave

This should spawn a window displaying a virtual keyboard. Use your touch screen, computer keyboard or mouse to play melodies on the virtual piano.

MIDI In

To listen for events originating from an external MIDI device you need to specify the name of the input device:

bash microwave devices # List MIDI devices microwave run --midi-in name-of-my-device microwave run --midi-in "name of my device" # If the device name contains spaces

MIDI Out

To enable playback through an external MIDI device you need to specify the name of the output device and a tuning method. The available tuning methods are full, full-rt, octave-1, octave-1-rt, octave-2, octave-2-rt, fine-tuning and pitch-bend.

bash microwave devices # List MIDI devices microwave run --midi-out name-of-my-device --tun-method octave-1 microwave run --midi-in "name of my device" --tun-method octave-1 # If the device name contains spaces

Soundfont Files

For playback of sampled sounds you need to provide the location of a soundfont file. The location can be set via the environment variable MICROWAVE_SF_LOC or the command line:

bash microwave run --sf-loc /usr/share/sounds/sf2/default-GM.sf2 steps 1:22:2

If you like to use compressed sf3 files you need to compile microwave with the sf3 feature enabled. Note that the startup will take significantly longer since the soundfont needs to be decompressed first.

Audio Options

The command-line enables you to set set up sample rates, buffer sizes and many other audio parameters. To print a full list of available options run:

bash microwave run help

Modular Synth – Create Your Own Waveforms and Effects

On startup, microwave tries to locate a config file specified by the --cfg-loc parameter or the MICROWAVE_CFG_LOC environment variable. If no such file is found microwave will create a default config file with predefined waveforms and effects for you.

LF Sources

Almost all waveform and effect parameters are real numbers that can update in real-time. To keep the waveforms engine performant updates are usually evaluated at a much lower rate than the audio sampling rate. LF sources, therefore, add control and expressiveness to your playing but aren't well suited for spectral modulation.

To define LF sources the following data types can be used:

Unfortunately, no detailed LF source documentation is available yet. However, the example config, microwave's error messages and basic YAML knowledge should enable you to find valid LF source expressions.

waveform_templates Section

The purpose of the waveform_templates section of the config file is to define the most important LF sources s.t. they do not have to be redefined over and over again.

Example: Using Pitch-Bend Events

Looking at the initially created config file the following template definition can be found:

yml waveform_templates: - name: WaveformPitch value: Mul: - Property: kind: WaveformPitch - Semitones: Controller: kind: PitchBend map0: 0.0 map1: 2.0

The given fragment defines a template with name WaveformPitch which provides values by reading the waveform's WaveformPitch property and multiplying it with the pitch-bend wheel's value in whole tones.

This means reacting to pitch-bend events is not a hardcoded feature of microwave but a behavior that the user can define by themself!

Example: Using the Damper Pedal

A second important template from the initial config file is the following one:

yml waveform_templates: - name: Fadeout value: Controller: kind: Damper map0: Property: kind: OffVelocitySet map1: 0.0

The given template provides a value describing to what extent a waveform is supposed to be faded out. It works in the following way:

While a key is pressed down, OffVelocitySet resolves to 0.0. As a result, Controller, as well, resolves to 0.0, regardless of the damper pedal state. Therefore, the waveform remains stable.

As soon as a key is released, OffVelocitySet will resolve to 1.0. Now, Controller will interpolate between 0.0 (damper pedal pressed) and 1.0 (damper pedal released). Ergo, the waveform will fade out unless the damper pedal is pressed.

Like in the example before, reacting to the damper pedal is not a hardcoded feature built into microwave but customizable behavior.

How to Access Templates

Just provide the name of the template as a single string argument. Examples:

yml frequency: WaveformPitch

yml fadeout: Fadeout

waveform_envelopes Section

Every waveform needs to refer to an envelope defined in the waveform_envelopes section of the config file. Envelopes transfer the result of the waveform's AudioOut buffer to the main audio pipeline and limit the waveform's lifetime.

An envelope definition typically looks like the following:

yml waveform_envelopes: - name: Piano amplitude: Velocity fadeout: Fadeout attack_time: 0.01 decay_rate: 1.0 release_time: 0.25

with

waveforms Section

The waveforms section of the config file defines the waveform render stages to be applied sequentially when a waveform is triggered.

You can mix and match as many stages as you want to create the tailored sound you wish for. The following example config defines a clavinettish sounding waveform that I discovered by accident:

yml waveforms: - name: Funky Clavinet envelope: Piano stages: - Oscillator: kind: Sin frequency: WaveformPitch modulation: None out_buffer: 0 out_level: 440.0 - Oscillator: kind: Triangle frequency: WaveformPitch modulation: ByFrequency mod_buffer: 0 out_buffer: 1 out_level: 1.0 - Filter: kind: HighPass2 resonance: Mul: - WaveformPitch - Time: start: 0.0 end: 0.1 from: 2.0 to: 4.0 quality: 5.0 in_buffer: 1 out_buffer: AudioOut out_level: 1.0

While rendering the sound three stages are applied:

  1. Generate a sine wave with the waveform's nominal frequency F and an amplitude of 440. Write this waveform to buffer 0.
  2. Generate a triangle wave with frequency F and an amplitude of 1.0. Modulate the waveform's frequency (in Hz) sample-wise by the amount stored in buffer 0. Write the modulated waveform to buffer 1.
  3. Apply a second-order high-pass filter to the samples stored in buffer 1. The high-pass's resonance frequency rises from 2F to 4F within 0.1 seconds. Write the result to AudioOut.

To create your own waveforms use the default config file as a starting point and try editing it by trial-and-error. Let microwave's error messages guide you to find valid configurations.

effect_templates Section

This section is completely analogous to the waveform_templates section but it is dedicated to work in combination with the following effects section.

effects Section

The effects section of the config file defines the effects to be applied sequentially after the waveforms have been rendered.

Use the following config as an example to add a rotary-speaker effect to your sound.

yml effects: - RotarySpeaker: buffer_size: 100000 gain: Controller: kind: Sound9 map0: 0.0 map1: 0.5 rotation_radius: 20.0 speed: Controller: kind: Sound10 map0: 1.0 map1: 7.0 acceleration: 6.0 deceleration: 12.0

The given config defines the following properties:

Live Interactions

You can live-control your waveforms with your mouse pointer, touch pad or any MIDI Control Change messages source.

The following example stage defines a resonating low-pass filter whose resonance frequency can be controlled with a MIDI modulation wheel/lever from 0 to 10,000 Hz.

yml Filter: kind: LowPass2 resonance: Controller: kind: Modulation map0: 0.0 map1: 10000.0 quality: 5.0 in_buffer: 0 out_buffer: AudioOut out_level: 1.0

If you want to use the mouse's vertical axis for sound control use the Breath controller.

yml resonance: Controller: kind: Breath map0: 0.0 map1: 10000.0

If you want to use the touchpad for polyphonic sound control use the KeyPressure template.

yml resonance: Linear: input: KeyPressure map0: 0.0 map1: 10000.0

Feature List

Help

For a complete list of command line options run

bash microwave help

License

microwave statically links against OxiSynth for soundfont rendering capabilities. This makes the binary executable of microwave a derivative work of OxiSynth. OxiSynth is licensed under the GNU Lesser General Public License, version 2.1.