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 1.12

. chords non-strummed were being strummed
. version edit retains original version naming (was overwriting rename)
. the edit version button allows you to move a version up or down in the list

Ratings and Reviews

4.7 out of 5
15 Ratings

15 Ratings

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!

wulll ,

Best sequencer on ios , bar none

There is nothing else that comes even close to the features in this sequencer. Take a look at the intro video on you tube, I guarantee you click buy now before it's halfway through...... I did, and am not disappointed. If you own a squarp pyramid... Throw it away you won't need it anymore.

McDrrrm ,

Anthony’s masterpiece

All of Anthony Saunders’ midi apps are the best in their genre, but this one is his masterpiece. It’s my go to app when it comes to creating bass lines and melodies, and if you’re doing Berlin School or any kind of dance music it’s a must have app.

It’s on offer at the moment, and so it’s a complete steal. It’s one of the few apps I couldn’t live without.


anthony saunders
209.5 MB

Requires iOS 9.3 or later. Compatible with iPhone, iPad and iPod touch.


English, Simplified Chinese

Age Rating
Rated 4+
© anthony saunders


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    Up to six family members will be able to use this app with Family Sharing enabled.

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