Comparison

MIDIRack vs SetClass

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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.

About

SetClass

Features
Read full description

SetClass is an interactive tool for exploring Pitch Class Set Theory — the analytical framework behind atonal and post-tonal music, from Schoenberg and Webern to contemporary composers. BUILD & HEAR Tap notes on the chromatic wheel to construct any chord, scale, or pitch collection. Hear it instantly with a jazz piano soundfont or built-in synthesizer. EXPLORE THE THEORY • Normal form, prime form, and Forte number for every set • Interval vector analysis • Transpositional and inversional symmetry • Z-relation detection TRANSFORM Apply serial operations: transposition (T0–T11), inversion, retrograde, retrograde inversion, and multiplication (M5, M7, M11). Watch the geometry change in real time. COMPOSE & SEQUENCE • Sequencer: build rhythmic patterns with serial transformations, arpeggios, swing, gate, and glide • Melody Generator: create melodic lines with contour control (free, rising, falling, arch) • Morph: blend smoothly between two sets with optional portamento • Export to MIDI or MusicXML FIND & GENERATE • Set Finder: enter any melody or chord and identify the pitch class set inside • Generator: produce sets by cardinality, symmetry (mirror, symmetric), and density LEARN Built-in theory reference covering pitch classes, normal form, prime form, interval vectors, Forte numbers, transposition, inversion, retrograde, symmetry, Z-relation, set class, morphing, and serial technique — with musical examples from Debussy, Schoenberg, Bartók, Webern, Berg, Stravinsky, and Messiaen. Available in English, Spanish, French, Italian, German, and Chinese.

Screenshots

MIDIRack4 screens
SetClass4 screens

Verdict

The call

The clearest difference is price: SetClass at $4.99 against MIDIRack's $14.99. SetClass also leads on in-app purchases (none vs 1). MIDIRack's advantage is update cadence (every 4 days vs every 3 months). On ads, device support 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

CostPrice · In-app purchases · Ads · Monetization

MIDIRack costs $14.99 and SetClass $4.99 up front. MIDIRack sells 1 one-off in-app purchase. SetClass asks for nothing beyond the download.

UpkeepUpdate frequency

MIDIRack ships an update every 4 days, SetClass every 3 months. The most recent releases landed on September 20, 2026 and October 3, 2026 respectively.

Scorecard3 real differences · 7 level
MIDIRack versus SetClass: the parameters behind the verdict, then further details
ParameterMIDIRackSetClass
Price$14.99$4.99 — better
Rating4.8 (8 ratings) — better—
Positive reviews66.7% of reviews—
Number of ratings8 — better—
Update frequencyEvery 4 days — betterEvery 3 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 — better18.0
Further details — not scored
Size28 MB88 MB
Age rating4+4+
DeveloperKai ArasMartin Adler

In-app purchases

1 purchases

MIDIRack

One-time1
  • Graph Editor Unlock$7.99
None

SetClass

No in-app purchases

Questions

Is MIDIRack free?
MIDIRack costs $14.99, and also offers in-app purchases.
Is SetClass free?
SetClass costs $4.99, with no in-app purchases.
Do MIDIRack or SetClass have ads?
Neither MIDIRack nor SetClass shows ads.
Which is updated more often, MIDIRack or SetClass?
MIDIRack ships an update every 4 days, and SetClass every 3 months. Most recently, MIDIRack was updated on September 20, 2026 and SetClass on October 3, 2026.

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