Press kit
MIDIRack for press.
MIDIRack is an iPad and iPhone app for building and playing custom MIDI control surfaces — every keyboard from KB-1, a suite of step sequencers, and an optional visual MIDI processing graph, running standalone or as an AUv3.
Icon, logo mark and full-resolution screenshots, plus the release text. Everything on this page may be used freely in coverage of MIDIRack.
Fact sheet
- Name
- MIDIRack
- Developer
- Numerical (Kai Aras)
- Category
- Music · MIDI controller, sequencer and processor
- Platform
- iPad (iPadOS 17 or later) and iPhone (iOS 17 or later, landscape) · standalone app + AUv3 (MIDI processor and instrument)
- Released
- August 18, 2026
- Latest version
- 1.1 — MIDIRack on iPhone, computer-keyboard play, XY mode on the MPE surfaces, custom Apple Pencil curves
- Price
- US $7.99 through September 5, 2026, then US $14.99
- Graph Editor unlock
- One-time in-app purchase · US $7.99 through September 5, 2026, then US $14.99
- Data collection
- None
- App Store
- https://apps.apple.com/app/id6779712751
- Website & manual
- https://numericalaudio.com/midirack
- Press contact
- hello@numericalaudio.com
Boilerplate
Copy-ready descriptions.
One sentence
MIDIRack is an iPad and iPhone app for building and playing custom MIDI control surfaces — every keyboard from KB-1, a suite of step sequencers, and an optional visual MIDI processing graph, running standalone or as an AUv3.
One paragraph
MIDIRack by Numerical is an iPad and iPhone app for building and playing custom MIDI control surfaces. It carries over all six touch keyboards from the developer's earlier KB-1 Expressive Keyboard Suite — piano, chord pads, scale keyboard, drum pads and two MPE controllers — and adds a suite of step sequencers, a freely arrangeable surface with per-control MIDI bindings, and a visual MIDI processing graph sold as a one-time unlock. It runs standalone and as an AUv3 MIDI processor or instrument inside hosts such as AUM, Logic Pro and Cubasis, and collects no user data.
About Numerical
Numerical is the one-person audio software studio of Kai Aras, developer of the KB-1 Expressive Keyboard Suite and other music apps for iOS.
Assets
Click any image for the full-resolution PNG, or take the whole kit.
Press release
FOR IMMEDIATE RELEASE
Numerical releases MIDIRack, a MIDI keyboard and sequencer workstation for iPad
August 18, 2026 — Numerical today released MIDIRack, an iPad app for building and playing custom MIDI control surfaces. It combines the touch keyboards from the developer’s earlier app KB-1 with a suite of step sequencers, a freely arrangeable surface, and an optional visual MIDI processing graph. MIDIRack runs standalone and as an AUv3 — a MIDI plug-in or an instrument — inside hosts such as AUM, Logic Pro and Cubasis.
MIDIRack is the successor to the KB-1 Expressive Keyboard Suite. All six of its keyboards carry over: piano, chord pads, scale keyboard, drum pads, and two MPE controllers — a Seaboard-style ribbon and a strings grid — with per-note pitch bend and pressure.
New to MIDIRack is a set of sequencers: drum, melody, chord and CC step lanes, a knob-per-step analog-style sequencer with slide and accent, and a matrix sequencer of up to 8×8 with six play directions. Lanes are edited directly on the surface and support per-step velocity, probability, trigger conditions and microtiming. Patterns hold four banks each, banks can be chained, and scene pads switch every lane at once.
Keyboards, sequencer lanes, knobs, faders, XY pads and displays are placed on a grid the player lays out. Each control carries its own MIDI binding — channel, CC and range — so a surface can address several instruments at once. Sixteen output channels and MPE routing are available per connection.
The graph editor, sold as a one-time in-app purchase, opens the patch that runs underneath every surface. It currently provides 65 node kinds, including arpeggiators, quantizers, euclidean rhythms, LFOs, MIDI delay, humanize, and generative sequencers based on cellular automata, Markov chains and chaotic attractors. Every keyboard on the surface is a routable node in the graph, and any knob or fader can be bound to any node parameter. Without the purchase, factory graph patches open and play; editing is locked. A built-in polyphonic synth and drum kit provide sound without an external instrument — the unlock adds a sampler and a loop slicer — and the app includes a full manual and a set of factory patches.
MIDIRack collects no user data.
Pricing and availability
MIDIRack requires an iPad running iPadOS 18 or later and is available on the App Store today. Through August 31, 2026, the app is US $7.99 and the Graph Editor unlock is US $7.99; regular prices after that are US $14.99 each. The launch window is also the upgrade moment for KB-1 owners — there is no separate upgrade path on the App Store. iPhone and Mac (Apple silicon) versions come later.
App Store: https://apps.apple.com/app/id6779712751
Website and manual: https://numericalaudio.com/midirack
Press kit: https://numericalaudio.com/midirack/press
About Numerical
Numerical is the one-person audio software studio of Kai Aras, developer of the KB-1 Expressive Keyboard Suite and other music apps for iOS.
Press contact
Kai Aras — hello@numericalaudio.com
Icon, logo mark, full-resolution screenshots, boilerplate and this release: https://numericalaudio.com/midirack/press