MIDI 101 – part 3 – the right sequence for iOS MIDI

MIDI icon

In part 1 of this MIDI 101 series aimed at iOS musicians, I tried to provide a brief introduction to MIDI as a technology – its history, the basis of the technology and, most importantly, its applications for the musician… all with a bit of an iOS context – iOS MIDI in the wider world of MIDI. In part 2, I covered some of the practical basics about using MIDI and, in particular, how to create MIDI data for musical uses if your music tech platform of choice happens to be iOS.

OK… so where next? Well, in this part – part 3 – we will turn our attention to MIDI sequencing… and, in particular, some of the different types of MIDI sequencing apps that there are available for iOS and what each might offer to the iOS musician.

Stand in line

When it comes to making use of MIDI, for most musicians, the most commonly used application is for recording music performances as MIDI data. Whether in hardware form or software form, systems that allow you to record MIDI performances in this way are termed ‘sequencers’… they allow you to record, and then playback, a sequence of MIDI notes.

That’s not all though… you can also edit that sequence of notes, whether that’s to correct the occasional duff notes, change the melody or chords being played or adjust the timing of the performance. Equally, because the performance has not been committed to an audio record, you can also adjust the sound that plays back the sequence of notes. You might well have started with a piano sound when you originally played the part but, if you want it played back via a different sound – whether that’s simply a different piano sound or an entirely different sound altogether – then MIDI can allow you to do that.

Well, it can allow you to do all of the things mentioned above (plus a good few more) providing the software you are using – the MIDI sequencer – has these features programmed into it. In terms of most desktop sequencers (and most of the well-known desktop sequencers now combine audio recording with MIDI sequencing; they are DAW/sequencers), whether that’s Cubase, Logic, Pro Tools, Reason, Digital Performer, Reaper, etc. – you get all this and plenty more. Indeed, the MIDI features provided by many of these up-market music production environments are slick, sophisticated and highly creative. However, that’s not to say that you have to use one of these fully-blown sequencer/DAW packages to get the job done; there are other approaches to the same general task of ‘sequencing’ MIDI notes.

MIDI sequencing can be a sophisticated, feature-packed experience in any of the top desktop DAW/sequencers - the example here shows the Key Editor in Cubase Pro with its 'piano-roll, time-line-based format.

MIDI sequencing can be a sophisticated, feature-packed experience in any of the top desktop DAW/sequencers – the example here shows the Key Editor in Cubase Pro with its ‘piano-roll, time-line-based format.


When it comes to iOS things are not quite so sophisticated at yet. While we have some respectable DAW/sequencers such as Cubasis (and, at the time of writing, Auria Pro soon to perhaps raise the bar for the iOS DAW/sequencer), there is not yet anything that, as a direct equivalent, can match what can be done on any of the more well-established desktop platforms.

However, that’s not to say there aren’t lots of very useful and creative tools for sequencing MIDI data under iOS; there are. Some – like Cubasis – mimic the approach used on the desktop but others perhaps provide different types of ‘sequencing’ tool… and while these alternative types of tool are also available for the desktop, given the absence of the ‘all singing, all dancing’ DAW/sequencer under iOS, these alternatives are more widely used by iOS musicians. Equally, given the unique opportunities the touchscreen can bring for music software control given a suitably imaginative developer, there are some iOS sequencing tools are unique to the mobile platform and do not really have an equivalent on the desktop.

Sequencers, sequencers and sequencers

Let’s take the broadest definition we can of ‘sequencer’ here…  and consider a number of the ways in which music software can allow you to play/generate/record a series of MIDI notes.

We could (but won’t as it would be a bit sad!) get very picky about how we classify or categorise the different approaches available but, for the sake of this discussion, let’s look at three types of ‘sequencing’; arpeggiators, pattern-based sequencers and time-line-based sequencers.

Many desktop DAWs also have dedicated MIDI editing tools for drum parts.

Many desktop DAWs also have dedicated MIDI editing tools for drum parts.

Arping on about it

OK, so some folk might not choose to think of arpeggiators as ‘MIDI sequencers’ and perhaps at their most basic (as found when built into some more basic iOS synth apps), they might not be the most exciting or flexible of options. However, with a few bells and whistles added, any arpeggiator can be a heck of a creative companion and there are some decent examples to be found amongst the many iOS music apps that populate the iTunes App Store.

As this series is primarily aimed at the MIDI (and maybe music tech in general) newbies, perhaps I’d better start with as explanation of what an arpeggiator actually is. In essence, and at their most basic, arpeggiators take all the notes you are currently playing on your MIDI keyboard as a chord and, instead of playing them all at the same time, ‘plays them as a series of individual notes. In effect, what you get is a ‘sequence’ of notes played one after the other. And, if you shift your hand and play a different chord, then you get a different sequence of notes that match the new chord.

If your keyboard skills are a bit basic (that’s me then) then this is actually a rather wonderful experience the first time you try it; hit a chord and – suitable settings for the arpeggiator taken as a given – what you get is a rhythmic sequence of notes in time with your overall musical project (or the tempo setting in your synth app) and ‘in tune’ (providing, of course, the notes in your chord are harmonically correct (that is, you are playing notes that all come from the same key/scale).

If your arpeggiator offers a few of the more interesting options, then as well as simply stepping through your notes in a simple up/down pattern, you may find it allows you to play through multiple octaves, tweak the timing of the notes to add some groove or swing, adjust the lengths of the notes, to change the musical length of the notes (1/4, 1/8, 1/16, 1/16 with a triplet feel, etc.), to randomise the order of the notes, to flip between different combinations of these setting on the fly (that is, to switch between different arpeggiator ‘patterns’ or ‘presets’) or various other features that add further interest to the sequence of notes created. With these kinds of options, even the most simple of chord sequences (played by even the most basic of keyboard players) can spring into life.

Follow the pattern

Pattern-based MIDI sequencing might be something that more obviously springs to mind when most iOS musicians (or music tech types in general) thing about ‘MIDI sequencing’ as a concept. This is a format of sequencing that is very common in dance or electronic music contexts as these forms of music are often based upon short phrases that are repeated to create longer song sections. A second phrase might be used and repeated to create a second song section (the chorus as opposed to the verse) and, to keep things interesting, the occasional variation to the phrase might be thrown in for good measure.

Each of these phrases are generally of a fixed length – between 1 to 8 bars, for example – and each phrase is created within a ‘pattern sequencer’. This is often represented as a grid, with pitch on the vertical axis and time on the horizontal axis. However, in its most common format, the ‘time’ is divided into a number of fixed length steps. A common example might be where 16 steps represent a single bar but most pattern-based sequencing environments allow you to vary the step length to suit your musical needs.

So, if we are creating a synth bass part, we might, for example, create a 2-bar pattern, where each bar has 16 steps (so the pattern as a whole has 32 steps). The pattern-based MIDI sequencer might then present us with a suitable grid and, whether it’s a mouse on the desktop, or a finger on the touchscreen, we can simply tap within the gird to add notes of the required pitch (vertical axis) and time position (horizontal axis) as we see fit. If you don’t want a note at a particular ‘step’ (time) then you just leave that column blank. Equally, most such pattern-based sequencers will also allow you to add notes that are of a different length that a single step (so you can create short or long notes.

One further bit of nomenclature; when a pattern-based sequencer is based upon a step system, it can also be referred to as a ‘step sequencer’….

So, this pattern/step-based sequencer environment allows us to create a pattern for our MIDI performance. And, if we are lucky, it will let us create several different patterns so we can, eventually, create some different music sections. And, on top of that (hopefully), it then allows us to construct a ‘song’ by chaining those different patterns together and, when required, specifying how many times each pattern should be repeated. For example, our bass line might use a 2-bar pattern ‘A’ repeated 4 times for the verse, before switching to a 4-bar pattern ‘B’ that’s repeated twice for the chorus section.

The next step would be to add multiple ‘lanes’ to this pattern/step sequencer so that you could create patterns for your drums, bass synth, pad synth, chord parts, melody hook, etc…. and to allow these patterns to be arranged alongside each other… hit playback and all your MIDI instrument sound sources play back their various pattern in sync… You have a full MIDI-based musical arrangement performed based upon a small number of MIDI patterns with the notes sequenced within each pattern and the patterns sequenced within the overall ‘song’.

There are all sorts of advantages to this kind of arrangement. First, it allows you to build a song structure very quickly based upon just a few simple pattern ideas. In addition, most such sequencing tools allow you to easily copy a pattern and then modify it to create a variation so you can keep things interesting. Also, as the song is build of patterns that are repeated at various stages through the song, if you decide to change something, (for example, add an extra note), you can do this in (for example) pattern ‘A’, and all instances of pattern A will then be changed to reflect that.

In dance and electronic music styles, where repetition of parts and song section is very common (although repetition is, of course, something common to almost al forms of music), this pattern-based approach provides a very straightforward means of composition.

On something of a (piano) roll

By the time you get to the more ‘traditional’ desktop DAW/MIDI sequencers, it is more usual to see what might best be described as a time-line-based approach to MIDI sequencing. Most desktop recording environments adopt a ‘project’ window view that has your various audio and MIDI tracks organised in a vertical order while the horizontal component represents time usually displayed in terms of musical bars (although you can also use actual time or numbers of frames (when working for film/TV) if that suits your needs better).

As you record on each track, therefore, the audio or MIDI data is simply placed on the track at the appropriate time point and you can scroll left/right through your project to move along the timeline. However, with either audio or MIDI, you don’t have to just start recording at bar 1 and then continue in a single take under bar 101 (or however long the musical project happens to be); you can record in shorter sections, whether that be just a short four bar phrase or a 16 bar song section… the choice is yours.

You could, therefore, simply record your MIDI parts as short (a few bars long?) sections and then copy and paste them along the timeline to construct the song structure required. This is, in effect, not so different from working with a pattern-based sequencer. Alternatively, you can just start at the first bar and keep playing to capture a ‘real’ MIDI performance of the whole song with all its natural variation, etc. that might give it a more ‘human’ feel.

As with pattern-based MIDI sequencing, you can also go into a MIDI performance that you have already recorded and edit it in various ways. In a top-of-the-line desktop MIDI sequencer, the options here can be quite staggering…. from simple note editing to very sophisticated quantising (adjusting and refining the timing of the notes within the performance).

However you approach the recording and arranging process of your MIDI tracks, when you do come to edit them, the odds are you will be presented with something known as a ‘piano roll’ editor. This name derives from the old mechanical pianos that used to be able to play back a tune based upon patterns of holes punched into a roll of paper. On screen, in a modern DAW/MIDI sequencer, when you choose to edit a MIDI part, you see the ‘virtual’ version of this roll of paper…. with the pitch of notes arranged vertically and the time position (bars and beats) arranged along the horizontal axis.

In fact this format is not so different from some pattern-based editors albeit that you don’t have to work in short 1, 2, 4, 8 or 16 bar ‘patterns’ if you don’t wish to. However, in most piano roll editors, you are also not confined to certain step sizes; notes can be placed anywhere and can have any length that you like… and depending upon just how accurate and consistent your playing is, that might (or might not) be a good thing in terms of the expression/human feel you can impart in your performance.

Don’t worry though; if you need metronomic dance-friendly consistency with timing and note lengths, most decent piano roll editors will allow you to apply some instant corrections to any sloppy playing via the various editing tools available. You do, however, have the choice based upon the musical needs of any specific project you are working on.

One and do note that some timeline-based MIDI sequencers can offer an alternative to the piano roll view if you specify that a track is being used to programme drum parts. Then, if you are lucky, you may well get offered a something slightly different with your different drum sounds arranged vertically and, again, time along the horizontal axis.

Which type of sequencer is best?

This is perhaps a bit of a daft question because the answer will depend very much upon what you want to use the sequencer for, the style of music you are working on and your own personal preferences. Indeed, while arpeggiators are perhaps a bit of a special case (a means to liven up some chord progressions), both pattern-based and time-line–based MIDI sequencing can be used for almost any musical style and their core functionality will have plenty of overlap.

That said, personal preference will most certainly come into it and, if you do any amount of MIDI sequencing within your music creation, the style and sophistication of the MIDI sequencing tools offered by the various music software you might consider using will probably play a big part in how much you ‘like’ working within one piece of software rather than another.

Example sequence

Under iOS, we actually have quite a number of apps that, in some form or another, offer the ability to sequence MIDI notes, from the humble (and occasionally not so humble) arpeggiator, through the very powerful pattern-based sequencers and towards something approaching (if, as yet, not quite matching) the desktop DAW/sequencer’s full-on time-line-based piano-roll MIDI recording/editing environment. And it is probably true to say that there are some apps that perhaps represent something that doesn’t fit perfectly into any of these three basic categories.

So, all that said, if you are just starting out with MIDI sequencing, what about a few examples of each approach that you could take a look at, explore, and see if they crank your particular ‘MIDI’ handle?

In terms of arpeggiators, there are some nice examples built into a number of the popular iOS synth apps. Amongst those, I enjoy the arps built into apps such as Arturia’s various synths, FM4, Laplace and Z3TA+

ISEM includes a basic - but very useable - arpeggiator function.

ISEM includes a basic – but very useable – arpeggiator function.

In terms of something at the more basic end of the arp spectrum, the features built into Arturia’s iSEM and iMini are good fun. In each case, you get a fairly traditional take on tempo sync, number of octaves and a few variations in the direction of the note playback (so nothing too taxing to master) but, because the synth sounds themselves are excellent, they just sound brilliant anyway. FM4 from Primal Audio offers a similar ‘keep it simple’ approach but, again, sounds great anyway.

If you want to move up a step or three in terms of features, then the arpeggiator built into Laplace (by developer iceWorks) is worth exploring. Indeed, this starts to bring in elements of pattern-based sequencing into the process and you get a step-based pattern editor that allows you to both define which steps notes will play on and to add accents, glides, staccato and octave settings to create additional interest.

If you want to go a little bit further upmarket, the arpeggiator function built in to Cakewalk’s Z3TA+ is quite interesting. This almost takes some of the elements of a pattern-based sequencer and melds them with the automatic ‘more notes than I’m playing’ elements of a standard arpeggiator. It also includes ‘groove’ functions to help give the pattern a bit of extra feel.

Z£TA+'s arpeggiator features actually crosses over into pattern-based sequencing.

Z£TA+’s arpeggiator features actually crosses over into pattern-based sequencing.

However, if you don’t want to be stuck with a particular choice of synth, there are a number of dedicated arpeggiator apps available on the App Store. While these may feature their own internal sound engines, these apps are really designed for you to use the arpeggiator features to drive another synth app of your choice; the arpeggiator app creates the MIDI based upon your settings/input and then sends that MIDI data on to your target synth or to your MIDI recording app.

My own personal favourite app of this type is Laurent Colson’s StepPolyArp. The basic feature set is impressive; patterns up to 32 steps can be created and, as you then feed the app a chord via MIDI, that pattern is recreated in realtime using the notes that you are playing in. You can create presets with 16 patterns and easy movement between these patterns, transpose, play patterns via a number of internal sounds or (more usually) send the MIDI data out to your favourite iOS (or, with suitable MIDI connectivity, desktop/hardware) synths, sync to MIDI clock if linked to a DAW/sequencer, generate random patterns, add controller data to your patterns… and a whole bunch more. And this is all topped off with a very attractively designed interface that is pretty easy to use via the touchscreen. StepPolyArp is currently priced at UK£9.99 and worth every penny.

StepPolyArp - a flexible and well-featured arpeggiator for the iOS musician.

StepPolyArp – a flexible and well-featured arpeggiator for the iOS musician.

When it comes to pattern-based (and/or step-based) sequencing under iOS, there are a number of apps that adopt this approach. However, unlike with time-line-based MIDI sequencing on the desktop where all the major candidates offer something that is broadly similar, pattern-based sequencers under iOS often bring their own (sometimes quirky) take on the genre.

Perhaps my favourite app that is built around pattern-based MIDI sequencing is Korg’s Gadget. While the various ‘gadgets’ (virtual instruments) built into Gadget are impressive in their own right, for me, it is the rather elegant way Korg have implemented the pattern based sequencing – with the very clever use of ‘scenes’ and one of the better pattern editing systems currently available via the touchscreen under iOS – that makes the app feel so slick. It might not be the cheapest ‘all-in-one’ electronic music production app available on the App Store but it is mightily impressive and well worth the UK£29.99 asking price.

Gadget uses a combination of pattern-based sequencing that can be organised into 'scenes' to create a song structure.

Gadget uses a combination of pattern-based sequencing that can be organised into ‘scenes’ to create a song structure.

Another type of pattern-based sequencing often forms the basic sequencing provision in ‘drum and groove’ virtual instruments. Such instruments are often recreations (tributes to) classic hardware such as the Akai MPC, with their drum pad performance options and sample triggering. There are a number of such apps available under iOS but my personal favourite of the current crop would be UVI’s BeatHawk. The user interface is slick and, even without the impressive pattern-based sequencing, the feature set and included samples are impressive. However, the pattern creation and sequencing tools are very well designed and, if you like the drum/groove box approach, this is a very good example of the genre.

Creating patterns within BeatHawk is very much a 'hands-on' task (you play the patterns in using the pads) but these can then be easily arranged into a sing structure.

Creating patterns within BeatHawk is very much a ‘hands-on’ task (you play the patterns in using the pads) but these can then be easily arranged into a sing structure.

As with arpeggiators, you can, of course, also find dedicated pattern-based sequencing apps. And while it may not be the easiest app to get started with, for me, Sugar Bytes’ Thesys is a start performer in this class. As with StepPolyArp, Thesys includes its own sound engine but it is really intended to allow you to construct pattern-based sequences and then send those on to other iOS synths. Up to 16 patterns can be created within a Thesys project and these can then se sequenced into a ‘song’ structure or triggered via MIDI. However, what sets Thesys apart is the depth of features offered in the pattern sequencer itself… this is powerful stuff but it is also what gives the app a bit of a learning curve. Still, Thesys replays a little study with results…

Thesys - not for the faint-hearted but a it is very powerful step/pattern sequencer.

Thesys – not for the faint-hearted but a it is very powerful step/pattern sequencer.

If you want something that is perhaps a bit more accessible then midiSequencer – by developer Tony Saunders – is well worth a look. This is a very retro-inspired step-sequencing environment that harks back to hardware sequencers of old but, under the hood, is actually very well featured. For a classic vibe presented for a modern format, midiSequencer is well worth a look.

Fancy a more retro feel to your step/pattern sequencer? Try midiSequencer then...

Fancy a more retro feel to your step/pattern sequencer? Try midiSequencer then…

I’d like to mention one further app within this brief introduction to iOS pattern-based sequencers; Oscilab. This app – by developer 2beat – is sort of a pattern/step-based sequencing environment but it is also part virtual instrument, part groove box and part generative music tool. Rather like Gadget, Oscilab uses ‘scenes’ (collections of patterns for each of its six sound sources) so that you can arrange your patterns into a song-like structure.

However, what is really interesting is how those patterns are created in the first place. The two ‘drum’ instruments uses a fairly standard grid/step-based system but, for the melodic instruments, patterns of notes are created using combinations of multiple waveforms to control pitch… while the app ensure that the actual notes selected are always within the chosen key/scale. This is a pattern-based sequence creation tool that even a non-musician (or at least someone without formal/traditional musical skills) can use and never hit a duff note. The results can be brilliant and, at UK£7.99, Oscilab is a bit of a gem.

Oscilab - pattern-based sequencing with a bit of a touchscreen twist.

Oscilab – pattern-based sequencing with a bit of a touchscreen twist.

What about our time-line-based MIDI sequencers? Well, for the best examples of these we need to look at the sorts of iOS music apps that attempt to mimic what desktop DAW/MIDI sequencers have now been doing for a number of years. Again, as a personal choice, I’d pick Steinberg’s Cubasis as the best of the current crop. All round, this is a well-designed and well-implemented recording application with a user interface that never gets too busy yet still delivers a core set of features that will allow you to get most audio and MIDI recording tasks done. And, for me, as a long-term user of Cubase on the desktop, Cubasis is an obvious choice.

Cubasis features a very respectable piano roll style editor for working with MIDI parts.

Cubasis features a very respectable piano roll style editor for working with MIDI parts.

At the time of writing, however, we are probably only a few weeks (fingers crossed) away from the release of WaveMachineLab’s Auria Pro. The current version of Auria is an audio-only recording environment but the ‘Pro’ update – which WaveMachineLab have already demoed extensively – looks very impressive. If it runs well, and the feature set proves to be manageable given the size/specification of current iPad hardware, then Auria Pro promises to get iOS DAW/sequencers a significant step closer to those found on the desktop. Watch this space.

What next?

Having provided a bit of a taster for the different types of MIDI sequencing tools available under iOS, in the next instalment of this series – part 4 – I thought I might take a closer look at the sorts of things MIDI sequencing allows you to do. This will include some of the basics of general MIDI note editing – and the pros and cons of that under iOS – but also some of the other editing tools (corrective and creative) that a good MIDI sequencer can provide. Until next time….

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    1. For another option for piano roll DAW style editing take a look at Multitrack studio. The worlkflow is a little different but its pretty solid.

      • Hi Shadoe42…. I know some folks really like Multitrack Studio. I have dabbled but I suspect I’m so familiar with Cubase/Cubasis that most other DAW/sequencers feel a bit less comfortable to me…. I should give it some more time though I guess. Best wishes, John

    2. Ian Sainsbury says:

      Pro Midi was recently updated and has features I haven’t found anywhere else on ios. I’m not an Ableton Live user, but this may well be the closest we have on ipad, as it’s clip/scene based. It’s more powerful than the sequencer in Gadget (but not as pretty) as you can set up a clip with unlimited measures. That way, you could – for instance- have a drone that develops throughout a whole piece, or just a melodic line where a note could sustain between one scene and another. This drove me nuts when I realised I couldn’t do it on gadget. You can even have different time signatures simultaneously on different clips. In conjunction with state saving on Audiobus, this is a pretty comprehensive midi sequencer. Not without its faults, but my initial forays have been very encouraging and the developer is still active (just added a much needed metronome). Worth a look, John?

      • Hi Ian… it’s an app I have not really dug into… I’ll try and put that right soon. Best wishes, John

    3. Man, quick skim, my head is spinning with reading all that. Gonna take a while to digest all that.

      Probably longer than it took you to write it John. ;)

    4. Ian Sainsbury says:

      Excellent article, as always btw.

    5. Another great look at MiDi John!

      A couple of other options: i have to mention Auxy, of course; with its IAP for MIDI out its a very easy and pretty slick way to sequence.

      Yamaha’s Synth Arp and Drum Pad is an app that I finally got a chance to check out recently. I think it’s still free, and wow, it has a lot of functionality beyond just arpeggios and so far that I see it has solid MIDI functionality.

      BeatWave just had an update (I had downloaded that a long time ago). Checking it out again this week; it made me think of Auxy. Beatwave has some good sounds and if they had MIDI out it could be a real winner, as like Auxy it’s a slick and easy way to tap in notes in a running sequencer.

      Even though I have a bunch of Arps and sequencer apps now, I am really looking forward to Auria Pro.

    6. Hi John, Been reading your articles for hours and I think I found some really good stuff in the way of building a iOS Home Studio… Thinking to purchase M-Audio Oxygen 61 V4 at the moment. Been searching still, does it worth the money? And I want to use it (with Camera Connection Kit) On my iPad and on my Windows 8.1 Laptop. Is it suitable for both… Thanks for the useful stuff. Greetings from Turkey.

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