Scaler 3 vs IMPSY
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Scaler 3
This music theory workstation helps you discover chords, explore harmony, and build complete musical ideas. It offers a redesigned workflow, expanded creative potential, and powerful new capabilities for songwriting and music production.
- Discover music's key with MIDI and audio detection
- Access over 1,000 chord sets, keys, and modes
- Build intelligent chord progressions with automatic voice-leading
- Structure full musical ideas with Scenes and Arrange Page
- Transform chords into melodies, basslines, and phrases
- Explore harmony with Circle of Fifths and modulation tools
- Host AUv3 plugins and interoperate with desktop versions
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The world’s most popular music theory workstation, Scaler 3, is now available on iPad — updated to Scaler 3.3 with Multi-Bind, improved Detection, enhanced workflow and desktop interoperability. With a redesigned workflow, expanded creative potential and powerful new capabilities, Scaler 3 helps you discover chords, explore harmony and build complete musical ideas. The workflow doesn’t have to end with your finished chord progression - Scaler 3 can host AUv3 plugins and features a full arranger and mixer, letting it fit into your existing setup or become your entire creative environment for music theory. Browse Draw from over 1000 chord sets, keys and modes, organised by mood, artist and genre. Build chord progressions by dragging and dropping chords, and receive intelligent suggestions for what could come next. Create Explore harmonic possibilities using tools like the Sketch Pad, Explore page, Circle of Fifths and Modulation pathways. Scaler’s creative tools and music theory assistance help you move beyond common progressions and discover new musical ideas. Arrange Turn your progression into a full musical sketch with tracks for chords, bass, melodies and custom MIDI patterns. Use Multi-Bind to perform and loop multiple lanes at once, creating fast composition ideas and live performance workflows. Scaler 3 can generate MIDI for all sorts of instruments and adapt it to the needs of your song. Host AUv3 plugins to play your parts, transforming Scaler 3 into a powerful composition and MIDI production environment. Key Features • Discover your music’s key with MIDI and audio detection and explore compatible scales, modes and chord sets • Access over 1,000 chord sets, keys and modes organised by mood, genre and artist inspiration • Build intelligent chord progressions with automatic voice-leading • Use Scenes and the Arrange Page timeline to structure full musical ideas • Transform chords into melodies, basslines, arpeggios and phrases using Scaler’s Motions library • Explore harmony using the Circle of Fifths, chord substitutions, inversions and voicing tools • Experiment with modulation suggestions to move between keys • Record ideas directly with User Track and edit them in the piano roll • Perform one-finger chords and melodies using Bind MIDI • Route generated chords and performances to other music apps using AUv3 and MIDI output • Play progressions using internal instruments including pianos, synths and orchestral sounds • Works standalone or alongside apps like Logic Pro for iPad, GarageBand, AUM and Cubasis • Move between Scaler 3 on iPad and desktop by sharing presets, chord progressions and files Content • Thousands of chords, scales and harmonic possibilities • Artist chord sets created by musicians including Carl Cox, MJ Cole and The Temper Trap • Generate MIDI with hundreds of melodic phrases, basslines and performances • Internal instrument library including pianos, synths and orchestral sounds Perfect For • Songwriting • Music production • Composition • Learning harmony and music theory • Exploring new musical ideas What People Are Saying “Scaler 3 is an incredibly powerful music theory tool. It's a gamechanger for both beginners and seasoned producers.” -David Wills (Michael Jackson, Whitney Houston, Phil Collins) “Scaler 3 opens up a whole new world of possibilities… a fantastic gateway into harmony and composition.” -Daryl Bennett (Grammy-nominated composer) “Scaler 3 has evolved into a fully-fledged compositional toolkit. A triumph.” -Sound On Sound “Scaler 3 delivers the most comprehensive, powerful set of composition tools you can get.” -Attack Magazine “Scaler 3 takes everything that made Scaler 2 brilliant and makes it even better.” -The Sound Test Room Awards • KVR Readers Choice Awards - Winner 2025 • Plugin Boutique Awards - Best Music Theory Software 2025 • Sanjay C #1 Tool - Top Plugin of 2025 • #1 Music Theory App - Future Music Magazine 2024
IMPSY
This app acts as an AI MIDI partner, improvising musical responses to your playing. It can be used as an AUv3 plugin in DAWs or standalone, offering customizable AI models and MIDI mapping.
- AI-powered musical improvisation
- AUv3 MIDI Processor for DAWs
- Standalone Core MIDI virtual ports
- Customizable AI model loading
- Extensive MIDI mapping options
- VoiceOver and Dynamic Type support
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Jam with an AI MIDI partner on iPad and iPhone. IMPSY listens to what you play and improvises musical responses. Load it as an AUv3 MIDI Processor in AUM, AudioBus, Cubasis or Logic Pro for iPad, play it from a USB or Bluetooth controller (or the on-screen faders), and route its output to any instrument app. IMPSY also runs on its own: it appears as Core MIDI virtual ports (IMPSY In / IMPSY Out) and connects directly to a plugged-in controller, so you can play it without a DAW. How it works IMPSY runs a Mixture Density Recurrent Neural Network (MDRNN) on-device. Every note, control change or pitch-bend you send becomes input to the model, which predicts what comes next, including the timing of the response. Shape the conversation with: • Threshold: how long IMPSY waits between your input and its reply • Sigma Temperature: randomness of pitch and control values • Pi Temperature: randomness of which musical "idea" the model picks • Timescale: speeds up or slows down the response • MIDI Thru: passes your own playing through to the output alongside IMPSY's Connect anything • Map each model dimension to any MIDI message (notes, CCs or pitch-bend) on any channel, independently for input and output • Connect a controller directly, or use the always-on IMPSY In / IMPSY Out virtual ports • Import and export your mappings as TOML, compatible with the IMPSY Python toolkit Custom models IMPSY ships with a default 9-dimensional model trained for general musical interaction, but you can load any .tflite model trained with the open-source IMPSY research toolkit: synths, drum machines, lighting rigs, or anything that speaks MIDI. Accessibility IMPSY is built to work with VoiceOver and Dynamic Type. Every control is labelled, the sliders are adjustable by VoiceOver, and status shows as text, not colour alone. Full statement: charlesmartin.au/impsy-auv3/accessibility.html Compatibility • AUv3 MIDI Processor, no audio I/O • Hosts in AUM, AudioBus, Cubasis and Logic Pro for iPad, or any other AUv3 host that supports midi processors. • Also runs standalone with Core MIDI virtual ports and direct device connection • Requires iOS 17 • MIDI stays on-device. No network, no telemetry
Screenshots
Verdict
The clearest difference is price: IMPSY at Free against Scaler 3's $12.99. IMPSY also leads on device support (3 vs 1). Scaler 3's advantage is update cadence (fortnightly vs every 4 months) and ratings volume (171 vs 2). On ads, in-app purchases and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
IMPSY is free to download; Scaler 3 costs $12.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Scaler 3 holds the better App Store score, 4.7 against 4.5. That said, the two scores are not equally well evidenced: Scaler 3 has 171 ratings behind it against 2, so its average is the more settled of the two.
Scaler 3 ships an update fortnightly, IMPSY every 4 months. The most recent releases landed on November 5, 2026 and October 31, 2026 respectively.
| Parameter | Scaler 3 | IMPSY |
|---|---|---|
| Price | $12.99 | Free — better |
| Rating | 4.7 (171 ratings) — better | 4.5 (2 ratings) |
| Positive reviews | 56.7% of reviews | — |
| Number of ratings | 171 — better | 2 |
| Update frequency | Fortnightly — better | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPad | iPhone, iPad, Mac — better |
| Requires iOS | 16.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 1.1 GB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | Scaler Music | Charles Martin |
Customer experience
Scaler 3
IMPSY
In-app purchases
Scaler 3
No in-app purchases
IMPSY
No in-app purchases







