Quantum Sequencer 4+

multitrack midi step sequencer

anthony saunders

    • 4.4 • 22 Ratings
    • £7.99



Quantum is a performance midi sequencer which approaches music composition with an interactive creation processes - sometimes referred to as 'noodling'.

Where pattern or piano-role sequencers are good for music forms (intro/verse/chorus etc) or grid entry, Quantum's approach is built around the idea of a step being the focus - think of the step as a single note or chord written on a music sheet then add a lot of extra notation (like probability of playing or ornamentation say).

These highly detailed steps are then aligned into sequences (think melodies) that loop. You can have any length up to 64, but these can be further split into 4 sub-sequences that have their own set of sequencer parameters (like tempo, play direction, transpose etc).

To enter step parameters such as note pitch, velocity, gated length etc, 16 general faders are available which allow you to draw, drag, select copy/paste, inc/dec & link together to edit values. These are also midi learnable (midi cc or nrpn) to allow you to use control surfaces or midi controllers.

To aid you with faster control Quantum has loop actions which you can program in to carry out tasks when a sequence loops - e.g. transpose, randomise, start or load another sequence etc.

With up to 24 sequences playing Quantum introduces a mixer page allowing you to blend midi velocities. Built on the MidiSequencer engine, midi FX, devices & Controllers are now possible per sequence.

So why would Quantum be good for your setup? There are many midi enabled IOS & hardware synths that produce exotic timbres if you send them fast & varied midi controls that you just would not hear with keyboard playing or slow tempo tunes. Also, Quantum, embraces experimentation in melody creation and by copy/pasting allowing quick setup of arpeggios & counterpoint tunes that you can create & manipulate on the fly!

note : This app sends midi information - you need to use it in conjunction with any midi enabled iOS synth app (e.g. Sunrizer) to hear sounds

What’s New

Version 1.17

Added Bluetooth privacy fix
Latest Audiobus library
Record button pop-up text

Ratings and Reviews

4.4 out of 5
22 Ratings

22 Ratings

Midimania ,

Very complex..but ultimately brilliant

Update to my first review……I set Quantum up as described in my previous review, I removed all synths, then launched iM1 in track 1 and made sure it was set to Multi mode (inside the app), then pressed Play in Cubasis3 and WOW….notes and drums flying around everywhere, it sounded like a full orchestra practicing because I never expected to hear all the sequencer parts playing at the same time. The 8 part multitimbral iM1 is the perfect companion to Quantum Sequencer, now all 6 sequencer parts CAN be heard at the same time, it’s just fantastic, well…..it will be once I set the sequences to harmonise with each other.
Worthy of ⭐️⭐️⭐️⭐️⭐️⭐️⭐️⭐️⭐️⭐️

Wed 20 July.
I have just purchased Quantum, I primarily wanted to use It in Cubasis3, and already I have spent what seemed like hours trying to get a sound out of it, all was lost until I opened Audiobus 3 and selected Quantum as Audio, then set Cubasis3 as out….success, but when I set up 3 synths in Cubasis, then create 3 separate step sequences in Q, only one of the 3 synths selected can be heard at a time!
A very complex and mind boggling app, and no doubt incredibly brilliant, definitely need to read the manual with this one though.

Richtowns ,


This app goes deep, deep deep. The manuals well written. Ace!
This app will infect my dreams with crazy ideas waking me up in a cold sweat at 4am in the morning desperately reaching for my ipad to try out some never thought of madness that will start a new genre of music and will have its own weird and wonderful dance associated with it. The future will be shaped by this app, and it will be a good future.
Congratulations, Tony, I think youve made a classic

Developer Response ,

Great thats what I wanted from this app also - the ability to tryout crazy rhythms & create patterns on the fly But 24 part harmony would blow many minds, best to tame a few melodies at a time!

jfoifj ,

Has its problems

As a sequencer the ideas in it are good - ratcheting etc. It works fine controlling an iOS synth.

The problems start when trying to get it to work with a DAW on a computer. The Ableton Link feature is implemented in an incredibly confused and confusing way and even when the app claims to be running using Link it sends no MIDI to anything, anywhere. Live 10’s transport doesn’t work when using Quantum with Link either, so even if Quantum did send MIDI there’s no way to record it.

All the other ways to connect MIDI from an iPad to a Mac (cable, wi-fi etc.) don’t seem to work either and usually result in Live’s transport not working for playback or record.

What “help” there is is incomplete and useless for problem solving. Several hours searching on line turn up other people with similar problems but no answers that actually work.

A waste of money? No, unless you want to use it with a DAW or hardware synths. Which unfortunately I do. A pity because on the face of things Quantum is pretty much exactly what a touch-interface step sequencer should be - if only it actually worked properly.

App Privacy

The developer, anthony saunders, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary based on, for example, the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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