Cantus vs MIDIRack
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Cantus
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Cantus - Voicing Lab is an interactive harmony and chord-voicing tool by Nathaniel School of Music for pianists, composers, producers, and music theory students. Explore how notes move inside chords, hear voicings in context, and study color, tension, and modal relationships from the keyboard. Cantus is designed as a focused practice lab: pick a sound, inspect the voice leading, and build intuition for how harmony feels under your hands. FEATURES * Interactive chord and voicing explorer * Piano keyboard visualization * Modal and scale-based harmony practice * Voice-leading movement and pinboard-style comparison * Tone.js audio playback * Self-hosted fonts and bundled web assets * Works without an account BY NATHANIEL SCHOOL OF MUSIC Built for practical harmony learning, composition practice, and deeper chord fluency.
MIDIRack
Design custom MIDI control surfaces with a variety of instruments and sequencers. Unlock advanced features like a visual MIDI processing graph for complex routing and generative music creation. Use it standalone, as an AUv3 plugin, or to control desktop DAWs.
- Customizable touch surface design
- KB-1 keyboard suite with MPE support
- Advanced step and matrix sequencers
- Visual MIDI processing graph
- Built-in instruments and samplers
- Connects to desktop DAWs via USB or Bluetooth
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MIDIRack is a MIDI toolkit for iPad. Build a custom touch surface from the KB-1 keyboard suite, an all-new sequencer suite, knobs, faders, buttons and more — then unlock a visual MIDI processing graph (one time in-app purchase) and wire it into anything, from a simple custom controller to a full-on groovebox or a self-playing generative composer. Play it on its own and send MIDI anywhere, as an AUv3 plugin in your favourite host or a standalone instrument. THE BASE APP — PERFORMANCE SURFACE Design a custom control surface on a snapping grid: • The KB-1 keyboard suite — piano, diatonic chord pads, scale-locked keyboard, MPE Seaboard ribbon, MPE Strings grid (4ths), and a 4×4 GM drum-pad grid. Each is its own routable node with latch and octave shift. Successor to the KB-1 Expressive Keyboard Suite. • A suite of sequencers — drum, melody, chord, analog and CC step grids and a Matrix note grid, with a moving playhead, swing and microtiming. Per-step velocity, probability, tie and trigger conditions; pattern chaining and 4-pad scene switching for full arrangements; a knob-per-step analog machine that re-roots live as you play. • Knobs, faders, XY pads, buttons and live visualizers — bind to raw MIDI CC or graph parameters. On its own: a rich custom control surface builder — send MIDI and CC to any synth, app or hardware, no graph required. WITH YOUR DESKTOP DAW Expressive MPE hardware costs hundreds. MIDIRack turns the iPad you already own into a controller for Logic, Live, Bitwig, Cubase or any desktop DAW: • Two MPE surfaces — the Seaboard ribbon and the Strings grid send per-note pitch bend, slide and pressure to any MPE-capable instrument on your desk. • A controller that changes per track — MPE ribbon for the lead, drum pads for the beat, chord pads for the progression, faders mapped to CC for a mix move. Rearrange in seconds; save a surface per project. • Sequence it too — clock the step lanes to your DAW and drive its tracks. • Easy to connect — one USB cable to a Mac via IDAM (Inter-Device Audio and MIDI), or wirelessly over Bluetooth MIDI. No driver, no helper app. UNLOCK — MIDI GRAPH (in-app purchase) Wire MIDI In → processors → MIDI Out on a visual canvas: • 60+ node kinds — arpeggiators, scale/key quantizers, transposers, chords, echoes, swing, humanize, euclidean rhythms, random/generative melodies, LFOs, CC tools, an analog knob-per-step sequencer, a Matrix sequencer and a Counter. • Built-in instruments — Synth, Drums, a Sampler and a loop Slicer make sound right in the graph; no external synth required. • Emergence generators — Conway's Game of Life, Turing machine, Wolfram rules, Markov, bouncing balls, Lorenz attractor — for evolving, living patterns. • Presets — factory patches grouped by category (control surfaces, generators, keyboards, utilities): Amen Engine, Starfield, Conway Choir, Turing Bass, Cellular Drums… Save your own. ROUTING & MPE • MIDI Out exposes all 16 channels plus an MPE connector — multitimbral, multi-instrument setups. The built-in synth responds to MPE. • Every keyboard is its own node — process and route each one independently. PLAYS OUT OF THE BOX • Built-in polyphonic synth, drum kit, sampler & slicer or send MIDI to your gear via CoreMIDI and an always-on virtual port.
Screenshots
Verdict
The clearest difference is price: Cantus at Free against MIDIRack's $14.99. Cantus also leads on in-app purchases (none vs 1) and iOS requirement (15.0 vs 17.0). On update cadence, ads and device support 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
Cantus is free to download; MIDIRack costs $14.99 up front. MIDIRack sells 1 one-off in-app purchase. Cantus asks for nothing beyond the download.
Cantus ships an update every 5 days, MIDIRack every 4 days. The most recent releases landed on September 17, 2026 and September 20, 2026 respectively.
| Parameter | Cantus | MIDIRack |
|---|---|---|
| Price | Free — better | $14.99 |
| Rating | — | 4.8 (8 ratings) — better |
| Positive reviews | — | 66.7% of reviews |
| Number of ratings | — | 8 — better |
| Update frequency | Every 5 days | Every 4 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 3 MB | 28 MB |
| Age rating | 4+ | 4+ |
| Developer | Jason Zachariah | Kai Aras |
In-app purchases
Cantus
No in-app purchases
MIDIRack
- Graph Editor Unlock$7.99





