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ZenAudio ALK2

Live Looping Software By Bob Thomas
Published September 2018

ZenAudio ALK2

By allowing for complex arrangements and the use of audio, MIDI hardware and software plug-ins and instruments, ZenAudio’s unique software platform breaks the boundaries of loop performance.

SOS Gear Of The Year 2018 Editors PickLooping — the practice of creating, performing, recording and playing back (with or without overdubbing) a repeating musical motif in real time — has fascinated me since that mid-1990s moment when I first laid hands on the Lexicon JamMan. Although my own looping is primarily hardware-based, I’ve been following the development of software-based looping with interest and, occasionally, dabbling with intent. However, the need to carry a laptop, a fairly decent MIDI controller or two, an audio interface and all the other paraphernalia associated with a computer-based setup has (so far) kept me loyal to my hardware, especially when playing live.

The stage environment exposes some of hardware-based live-audio looping’s weaknesses. For example, the song or instrumental more often than not starts with the recording of a short looped backing phrase, which is then overdubbed until the desired density is reached, at which point the performance proper begins. To add further examples, there’s the mis-played part that necessitates a tap dance to fix the error, the difficulty in changing effects settings on the fly (especially if you’re playing guitar), or in changing the length of a loop. Then there’s the number of pedal presses often required to keep a performance under control, and (last, but not least) the need to loop MIDI data in this day and age.

ZenAudio’s recently released Mac-only ALK2 live looping software has the look of a hybrid between live audio/MIDI looping and sequencing. Its track-based workflow appears to transcend the limitations of hardware-based live looping by enabling and facilitating the creation, programming and presentation of complex, pedal-free, multitrack live looping performances in a DAW-style environment.

The Ideas Within

The first thing to realise about ALK2 is that it doesn’t follow hardware-based live looping’s paradigm of physical control of all functionality. Instead, you programme ALK2 in advance to automate all audio and MIDI-based live recording and looping, replay of any pre-recorded audio and MIDI tracks or clips, and the internal and external transmission of MIDI Note, switch and Continuous Controller messages by embedding these in your arrangement. When performing live, all you have to do is to start your track running, play or sing when necessary and ALK2 handles the rest.

ALK2 is also a VST/AU audio and MIDI plug-in host, with the ability to loop MIDI note data, with quantise and note repeat functionality. Its internal mixing is unusual in that each track that inputs or outputs audio can mix together an unlimited number of input sources and be routed to an unlimited number of outputs via an unlimited number of plug-ins. This ‘Symmetric Routing’ technology — in which each track acts as a virtual mixer — makes the creation of numerous track-to-track audio submixes and effects sends extremely quick and easy.

Automation is another area that exhibits a somewhat unconventional approach. Instead of being embedded in a track, each automation control is assigned to its own separate track, decoupled (as it were) from any audio/MIDI tracks, plug-ins or external hardware that it might be controlling. This allows a single hardware encoder or fader to control different tracks and different plug-in or hardware parameters at different times simply by defining the region(s) on the timeline at which it is active and assigning it to control the desired destination. Automation curves can also be drawn manually, with ALK2 supporting trackpad gestures to make life easier if that’s your thing.

ALK2 can host VST or AU plug-ins and virtual instruments.ALK2 can host VST or AU plug-ins and virtual instruments.


In ALK2 there are five track types: three Performance types (Audio, Instrument and MIDI), and two Automation types: Command (Note on/off) and Control (Continuous Controllers). Apart from the Audio track, all other track inputs accept only MIDI data. When it comes to outputs, the Audio and Instrument tracks output audio, the MIDI track outputs MIDI data (which can be sent to external devices via a suitable interface), whilst the two Automation types send only automation data.

Having chosen your project’s time signature and BPM (which you can edit at any time), the Track Panel allows you to set up the type and number of tracks that you require and their audio or MIDI inputs. You can also insert virtual instruments plus any effect plug-in(s) needed to process the tracks’ audio or MIDI outputs and, finally, create effect, MIDI and master sends, routing any external sends via the requisite interface I/O. Editing plug-ins is simply a matter of clicking individually on a track’s inserted plug-ins, which opens their control interfaces within ALK2.

Tracks can be freely named, renamed, ordered and reordered at will and, to speed up the task of track naming and organisation, virtual instrument tracks are named automatically from their plug-ins. ALK2 also contains a clever algorithm that gives tracks with similar names the same colours. So, for example, all tracks with ‘vocal’ in their title will be given the same colour.

Having created a track, the next step is to create and define the lengths of the Record and Play loops within it, by clicking and dragging the red (Record) and green (Play) pencil tools. In ALK2, record loops define the parts of a track during which you will be performing live. When you’re performing live with ALK2 in record mode, input signals can only be heard during record loops. Therefore, if you were singing the whole song live, you would need to draw a record loop that was the length of the song. Similarly, if you wanted to loop eight bars of either audio, virtual instrument or MIDI, your record loop would be that length. When created, a play loop will link automatically to the record loop last drawn in before it on the timeline. The number of play loops created, and their position, define the number and timing of repeats of the record loop that they are linked to.

A record loop will be automatically looped or truncated where necessary to fit its linked play loops and, although my personal preference is to create a new track for a new record loop, you can create multiple record loops in a single track. You can either draw in their linked play loops as you go along, or simply enter play loops and assign (and reassign) them afterwards as required.

An audio play loop can also replay an imported audio file — WAV, MP3, AIFF and FLAC are supported — and, similarly, a MIDI play loop can replay an imported MIDI file. Only WAV and MIDI files can be exported, however. Should you decide that you need to change the overall pitch of an imported loop or to move it in time, ALK2 has the facility to pitch-shift and to offset both audio and MIDI loops. Imported audio files can be tempo-matched to the existing track, although MIDI files can not.

ALK2 can accept both audio and MIDI inputs and outputs; the I/O is limited only by the interface(s) you have attached to your Mac.ALK2 can accept both audio and MIDI inputs and outputs; the I/O is limited only by the interface(s) you have attached to your Mac.

But Wait, There’s More!

I haven’t the space to look at all of ALK2’s track and loop editing features in detail, but rest assured that the program has everything that you’ll need in that department, and then some. When these are combined with the unlimited number of tracks, audio plug-ins, MIDI control hardware and virtual track inputs and outputs that I’ve already touched on, you’ll find that ALK2’s editing capabilities make composing and programming a looping performance piece an efficient and enjoyable task.

A benefit of ALK2’s unlimited I/O, track and controller options, when combined with its sequenced track input switching and controls, is that you are given the facilities to build up a complicated, large-scale, multitrack looping performance without having to use a multi-channel audio/MIDI interface. And — since multiple scripted and captured automation regions, each with its own individual target destination, can exist side-by-side on the same track — neither will you need a large MIDI controller to programme and perform complex automation combinations. Alongside this, should you wish to trigger a captured or scripted command live via a MIDI controller instead of automating the task, a Quantised Command function allows you to choose whether the triggering takes place immediately, at the end of a bar, or at the end of the command’s automation region.

When monitoring your audio and virtual instrument tracks, the selectable Hover Audition function is a useful timesaver that allows you to listen to a track simply by placing your mouse cursor over it.

Although software capable of pre-planned and programmed looping performances is not unknown, by their nature, these programs do not easily allow for spontaneous, mid-performance additional repetition of their loops. ALK2 gets neatly around this limitation with its Global Loop function, which can be set to continuously repeat either selected sections of the whole arrangement or of individual loops within it. This gives you the option of creating a performance where you could, for example, create a global loop to repeat a section of the full arrangement behind your live instrumental break for as long as you feel that inspiration demands or, alternatively, repeat a single loop until you have exhausted all its possibilities.

Finally, we come to ALK2’s ultimate lifesaver: the Panic function. Almost without exception, anyone who has given a live, loop-based performance will, at one time or another, have made a glaringly obvious mistake that starts looping whilst he or she performs a desperate tap dance trying to silence it. The nature of said dance depends on the looper in question, but most will disrupt the flow of the performance in order to give the musician an immediate second chance to get the loop right... and the audience the opportunity to cringe if things go wrong again.

When ALK2’s Panic function is invoked inside a record loop, a pre-recorded reference loop (if it exists) will drop in seamlessly, fill the record loop and play back in all following play loops. Creating a reference loop is simply a question of playing a record loop to your complete satisfaction in the comfort of your studio and then designating that performance as a Reference Clip. This means that should a live loop recording go wrong, you can hit your designated Panic footswitch and carry on without the audience realising that something has gone wrong.


ALK2 is an impressively thought-through program that has the potential to bring live looping into the performance mainstream. It allows you to structure a pre-programmed, live looping performance that keeps your audience engaged by making the initial build-up of looped tracks part of the pre-production, planning and programming process, enabling you to create loops of considerable length without losing your audience’s attention. In addition, by automating record and replay switching and controller tasks, the program frees you up to concentrate on performing.

On another level, with its unlimited audio and MIDI tracks, I/O and audio plug-in capacity, ALK2 offers larger ensembles the opportunity to engage in live looping performances with the same level of simplicity of operation as if they were all solo performers. The program also has a real potential as a songwriting assistant, allowing you to set up loops for each part of the song and freely experiment with different ideas and versions.

However, every god has feet of clay, and I was somewhat surprised to find that — at this time of writing — ALK2 does not output, or sync to, MIDI Clock/Song Position Pointer or MTC. A MIDI editor would be another a nice thing to have as, currently, any timing issues in a loop either have to be replayed or the loop has to be exported to a DAW for editing offline. Users report that the ALK2 development team are very responsive, which gives me confidence in the future of this rather excellent live looping platform.


Even though there are some very fine live looping software programs available, if you’re looking for a comparatively inexpensive, easy to use, comprehensively featured, hands-free live looping performance platform that can handle audio and MIDI loops and also has the ability to automate your entire performance, then ZenAudio’s ALK2 program is the only game in town. There’s the full version reviewed here, a track-limited (but full-featured) Solo version, and a 30-day free trial to take advantage of. So, if you think that ALK2 might be for you, there’s an online user manual and an extensive collection of informative instructional videos to check out.  


Although there’s no directly comparable looping program available, Ableton Live does enable users to plan and produce impressive looping performances, but at a greater cost.

On the other hand, if (like me) you think that the Oberheim/Gibson Echoplex Digital Pro is where it’s at for hardware audio looping, then Circular Labs’ Mobius program and Matthias Grob’s Echoloop VST plug-in could well be your first ports of call.

If MIDI-only looping is your thing, and you can read its French language manual, then Repetito just might be right up your street.

Return To Helsinki

Ian Stephenson performs using his melodeon, acoustic guitar, and ALK2 laptop setup.Ian Stephenson performs using his melodeon, acoustic guitar, and ALK2 laptop setup.

To illustrate how ALK2 works in the real world, see this screenshot from a live performance by musician, engineer, producer and studio owner Ian Stephenson (, pictured, of his own tune ‘Return To Helsinki’. You can find a SoundCloud recording of the actual performance at

If you follow the red-bordered Record loops along the timeline, you’ll see that, after a four-bar metronome count-in, Ian starts out by recording the 16-bar Loop 1 segment into the ‘Atmos Box’ track playing his melodeon, which is subsequently looped twice to end the performance. As that first record loop ends, Ian continues playing and ALK2 seamlessly switches the melodeon output to the input of the 32-bar ‘Box Tune’ Loop 2 section, then loops twice after an eight-bar pause. During that pause, ALK2 plays back a pre-recorded, one-shot, eight-bar audio clip on the Loop 1 track that was created by drawing in an eight-bar record loop on the Loop 1 track, recording the part and then Locking the performance, which changes the loop type from record to play.

The red outlines around some of the clips are Record loops: pre-determined ‘live’ sections in which audio and MIDI is passed through so that it can be heard live, but also recorded so that it can be repeated later. The green Play loops are the subsequent repeats. It is also possible to prepare or live-record MIDI automation.The red outlines around some of the clips are Record loops: pre-determined ‘live’ sections in which audio and MIDI is passed through so that it can be heard live, but also recorded so that it can be repeated later. The green Play loops are the subsequent repeats. It is also possible to prepare or live-record MIDI automation.

Underneath Loop 1 you’ll see the ‘Send to Blackhole’ Scripted Automation Control region for the effects send level from the ‘Box Tune’ Loop 2 to an instance of Eventide’s Blackhole reverb plug-in. That reverb is set up to produce a wash that adds sonic interest to both the eight-bar pause (during which Ian changes over from melodeon to acoustic guitar) and the last 16 bars of the performance. Scripted Automation Control regions allow you to enter pre-planned automation control curves and commands, whilst control data that is generated as part of the live performance — say, by a fader or a footswitch – is recorded in a Captured Automation record loop. Incidentally, the very bottom on-screen track is a Scripted Automation Command track that switches the ALK2 metronome on and off at appropriate points.

ZenAudio ALK2

When the pause comes to an end, ALK2 activates a pair of parallel 32-bar record loops: ‘Guitar Accomp’ (3A) and ‘Octave Bass’ (3B). These record loops allow Ian to record these alongside the first Loop 2 repeat without missing a beat. Loop 3A and 3B then repeat once. In case you’re wondering how Ian could play acoustic guitar and bass at the same time, his acoustic guitar is fitted with both a microphone and an RMC hexaphonic pickup system that drives the input of a Roland VG-99 — which is where the ‘Octave Bass’ comes from.

On the repeat of 3A and 3B, ALK2 (and Ian) switch to recording the 32-bar live loop ‘Guitar Tune’ (Loop 4). This is followed by the paired 32-bar live loops of ‘Octave Bass’ (5A) and ‘Atmos Guitar’ (5B), the first 16 bars of which are played by Ian under the second Loop 1 repetition to form the last 16 bars of the performance. During the last 16 bars of Loop 5B, you can hear the audience applause.

From an audience perspective, what they saw and heard (thanks to ALK2) was Ian playing melodeon for 48 bars, changing over to guitar within a four-bar phrase played under the reverb-drenched tail of the melodeon sound, and then playing guitar for 80 bars, ending in another big melodeon reverb tail (and audience applause). For both Ian and the audience, ALK2 oversaw a seamless performance, both visually and musically, that required no physical control input from the performer other than pressing a MIDI footswitch at the start.


  • Easy to use with a comprehensive feature set.
  • Loops both audio and MIDI.
  • Offers hands-free automated performance control.
  • Unlimited tracks, I/O and audio plug-in capacity.
  • Panic function helps minimise the effect of live performance errors.


  • No Windows version.
  • No MIDI clock sync.
  • No MIDI editor.


ALK2 is a well-featured live-looping software program that integrates live-action and pre-recorded audio and MIDI loops with automated, hands-free control to produce a uniquely specified performance platform.


ALK2 Solo €39, full version €199.

ALK2 Solo €39, full version €199.