gRainbow
Key Features
- Pitch-detecting granular engine powered by Spotify's BasicPitch machine learning model that segments audio into discrete pitches and finds up to six harmonically matched grain candidates per note
- Up to 150 simultaneous grains with polyphonic voicing across the full MIDI range for rich, layered textures
- Complete modulation system with four macros, three LFOs, and two envelope modulators assignable to nearly every parameter
- Per-note and per-generator parameter overrides for grain envelope shape, tilt, rate, duration, pitch spray, and pan
- Forward and reverse grain playback with host BPM sync for rhythmic granular patterns
- Open-source and cross-platform with native Apple Silicon support on macOS, plus Windows and Linux builds
- Redesigned v1.0 interface with color-coded pitch visualization that maps detected pitches to a rainbow display
Description
gRainbow by Strange Loops Audio is a pitch-detecting granular synthesizer that solves one of the biggest frustrations with traditional granular synths: the inharmonic tones and artifacts that come from pitch variations in your source material. Instead of relying on short, single-pitch clips, gRainbow encourages you to load longer, pitch-diverse audio files and lets its analysis engine handle the rest.
When you load a sample, gRainbow runs a pitch detection analysis powered by Spotify's BasicPitch machine learning model. It segments the audio into discrete pitches over time, assigns each a color on the rainbow-themed GUI, and finds up to six pitch-matched position candidates per note.
This approach guarantees harmonically agreeable grains without heavy time-stretching or manual pitch matching for MIDI input. The result is cleaner, more musical granular textures straight out of the box.
Version 1.0 introduced a complete redesign with a modernized interface, improved pitch detection accuracy, and a full modulation system featuring four macros, three LFOs, and two envelope modulators. Parameters including grain shape, tilt, rate, duration, pitch spray, and pan can be overridden at the per-note and per-generator level.
The synth supports up to 150 simultaneous grains, polyphonic voicing across the full MIDI range, forward and reverse grain playback, and host BPM sync. It ships with a 10-preset starter pack and is open-source under an active GitHub repository.
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Frequently Asked Questions
How does gRainbow differ from traditional granular synthesizers?
Traditional granular synths often produce inharmonic tones when the source material contains pitch variations, requiring short single-pitch clips for clean results. gRainbow uses machine learning pitch detection to analyze longer, multi-pitch audio files and automatically find harmonically matched grain positions for each MIDI note, eliminating the need for manual pitch matching and reducing time-stretching artifacts.
What is the BasicPitch ML model used in gRainbow?
BasicPitch is Spotify's open-source machine learning model for polyphonic pitch detection. In gRainbow, it analyzes loaded audio files to segment them into discrete pitches over time, enabling the synth to find up to six pitch-matched grain candidates per note. This provides more accurate and reliable pitch tracking than traditional DSP-based methods.
Does gRainbow support Apple Silicon Macs natively?
Yes, gRainbow runs natively on Apple Silicon (M1/M2/M3/M4) Macs as well as Intel-based Macs. It is available as a VST3, AU, and LV2 plugin plus a standalone application for macOS, Windows, and Linux.
Can gRainbow sync grain parameters to the DAW tempo?
Yes, gRainbow includes an option to sync rate parameters to the host BPM. This allows you to create rhythmic granular patterns that lock to your project tempo, which is especially useful for beat-aligned textural work and evolving pads.
