The new Note Stack and Pitch Control MIDI plug‑ins are included in all versions of Pro Tools.
Pro Tools has upped its MIDI game. What can the new MIDI plug‑ins do?
It is widely held that MIDI isn’t something that Pro Tools does best. Looking at the history of the program and its counterparts like Logic and Cubase, this is understandable. Cubase and Logic started life as MIDI sequencers, which over time gained audio capabilities as computers became fast enough to handle multitrack digital audio processing natively. Pro Tools has a rather different history, in that it started life as a DSP‑powered audio workstation system at a time when computers weren’t powerful enough to perform these tasks without help.
Over time, Pro Tools gained MIDI functionality and, ultimately, MIDI sequencing software and audio workstations converged into the modern DAWs we recognise today. Much of the negativity some people attach to the MIDI side of Pro Tools is based on received wisdom about MIDI as it was in Pro Tools years ago. When I started using Pro Tools 5 MIDI was, to put it politely, basic; but that was a long time ago, and things have changed a great deal. While some MIDI features are still missing from Pro Tools, one of the biggest gaps was addressed in Pro Tools 2024.3 with the addition of MIDI plug‑ins, along with an overhaul of MIDI routing to accommodate them.
Much of the negativity some people attach to the MIDI side of Pro Tools is based on received wisdom about MIDI as it was in Pro Tools years ago.
Plug‑in Power
There are now six MIDI plug‑ins included in Pro Tools. These plug‑ins share the same AAX architecture as audio plug‑ins in Pro Tools, and are accessed from the insert slots on Instrument tracks. They cannot be instantiated on MIDI tracks because MIDI tracks lack the insert slots in which to instantiate them.
The fact that the MIDI plug‑ins co‑exist with AAX plug‑ins and virtual instruments might seem counterintuitive: MIDI and audio I/O are kept distinct from each other in Pro Tools. But this is a distinction which isn’t made quite so rigorously in other DAWs. For example, in Reaper a track is just a track, with no need to designate it as audio or MIDI. I like having MIDI plug‑ins in the insert slots, but it’s important to note that a MIDI plug‑in following an instrument plug‑in will interrupt the signal flow and result in silence — plug‑in order is important.
Three of the newcomers are ‘in house’ MIDI plug‑ins, and these are included with all tiers of Pro Tools, including Intro. These Avid plug‑ins are intended to perform utility processing, and at present comprise Note Stack, Pitch Control and Velocity Control. At first sight it might seem that these plug‑ins are duplicating facilities already available in Pro Tools, so how are they different from what is already on offer?
The original way to manipulate MIDI data, other than by manual editing, was by using the Event Operations window. This window received an interface overhaul in Pro Tools 2023.6; rather than each page being selected from a drop‑down menu, they are now accessible simultaneously, with each section accessed using disclosure triangles, which is much more convenient. As well as control of quantise, this window offers velocity and pitch manipulation, and as such, does overlap with what is offered by the new Avid MIDI plug‑ins. We can see Event Operations as the MIDI equivalent of AudioSuite processing, in that the results are non‑real‑time and are ‘baked into’ the MIDI clip.
Property Development
An alternative to directly manipulating MIDI data on the timeline is to use MIDI Real Time Properties. As the name suggests, this allows real‑time processing of MIDI data on a track or clip basis. The processing available is utilitarian in nature: quantise, transpose, note delay/advance, duration and velocity control. The Real Time MIDI Properties feature is much more usable if you enable the ‘Display events as modified by real‑time properties’ preference, which means that while the underlying MIDI data can remain unmodified, you will actually see what you hear.
MIDI Real Time Properties also allows you to adjust MIDI data as it’s playing, but with less flexibility than the new plug‑ins.
With two very capable ways of manipulating pitch and velocity already available, what advantages are there to accessing similar features using the new AAX plug‑ins? Apart from the convenience of putting MIDI processing in the same place as audio processing — in the plug‑in insert slots — the biggest immediate benefit is that everything in a MIDI plug‑in is automatable. This is well illustrated by Note Stack. This plug‑in seems rather dry in nature: on first inspection, it allows you to stack notes by octave and semitone. The transposition isn’t related to key signature, and as such, it seems like it wouldn’t bring much to a composition. However, the ability to automate parameters makes things considerably more interesting. For example, the abilit to automate the offset while also automating the Note parameter, which enables/disables the note, encourages experimentation and introduces elements of unpredictability. However, it is the Probability parameter that brings the most immediate rewards. Setting Probability to a value lower than 100 percent means that Note controls the likelihood of that note sounding, and can introduce complexity and interest to a part.
The Pitch Control and Velocity Control plug‑ins add greater flexibility compared to Real Time MIDI Properties. The ability to include or exclude MIDI data based on pitch or velocity in both plug‑ins opens up interesting possibilities. Pitch Control offers transposition in key with the Key Signature Ruler, and Velocity Control offers more flexibility than the two‑parameter Vel section of Real Time MIDI Properties. Whereas the latter simply allows velocity data to be globally added to, subtracted from or scaled, Velocity Control can be much more selective, allowing you to achieve something closer to compression. For example, setting the Velocity Range to only process notes above a velocity of 100, and setting Scaling to 80 percent, means the dynamics of lower velocities are left unaffected while notes with velocities greater than 100 (the ‘threshold’) will be softened.
Here, Velocity Control is processing the MIDI data on the instrument track (top), and recording the processed MIDI notes onto the track below, via MIDI Chain.
In the screenshot, I have Velocity Control set up to as a MIDI compressor, acting on the Inst 1 track. In the I/O section of the lower MIDI track, I’m recording the output of Velocity Control using the MIDI Chain. This is central to how this new system works. It’s similar to an internal bus for MIDI, and as well as allowing MIDI data to flow through a chain of MIDI plug‑ins, it can be used to route MIDI data between tracks, for example to record the MIDI output of an arpeggiator.
Party Time
This brings us neatly to discussing the third‑party MIDI plug‑ins which have been introduced so far. The fact that these are AAX plug‑ins, and that half of them are from third parties, indicates that the future will include more offerings from outside the Avid stable. These third‑party processors are focused more on generative MIDI processing, and include Modalics EON Arp, AudioModern’s Riffer and Pitch Innovations’ Grooveshaper Lite. Rather than processing your MIDI, these are designed to generate new MIDI data of their own, and since you you can print their MIDI output to a track via the MIDI Chain and then edit it, it’s very much a case of keeping what you like and changing what you don’t.
The Modalics arpeggiator is particularly welcome... and when used in combination with Note Stack things can get really interesting.
The Modalics arpeggiator is particularly welcome; it’s deep, and when used in combination with Note Stack, things can get really interesting. In line with the ‘idea generation’ role of these generative plug‑ins, Riffer and Grooveshaper Lite both incorporate a dice button which will generate a random starting point from which to develop ideas. In the future I’d expect to see more products from third‑party developers ported to AAX. Given Avid’s investment into the producer market, particularly with the introduction of Pro Tools Sketch, MIDI production is an important area, and these new MIDI options open up lots of scope for new features and products.
One thing I would like to see, though, is a MIDI delay plug‑in. I’ve worked around its absence by duplicating a track and using MIDI Real Time Properties’ Delay function to create MIDI delays, but this is rather labour‑intensive, and a dedicated plug‑in might have extra features like individual MIDI Chain outs for each delay tap. And if each tap could have a Probability parameter, some very cool, unpredictable delay effects could be created...
Generative AI has been developing at pace, and MIDI plug‑ins seem particularly well suited to this technology. Where audio artefacts are often the limiting factor on AI audio, these constraints don’t apply to MIDI, so MIDI plug‑ins might have arrived at an ideal time.