You are currently viewing Review of Scaler – chord detection and creative chord progression creator utility (VST/AU/AAX) by PluginBoutique

Review of Scaler – chord detection and creative chord progression creator utility (VST/AU/AAX) by PluginBoutique

PluginBoutique have introduced Scaler, a unique and inspirational MIDI effect that makes finding chords and progressions intuitive and fun. With note detection, scale selection and chord suggestions, Scaler is a comprehensive but easy-to-use toolbox that will help anyone make better music.

It is available in AAX, VST and AU formats as 32 & 64 bit versions from PluginBoutique’s website. It is typically priced at £39.95

A first of its kind, Scaler can determine what key and scale you’re in and suggest chords that match your music, or it can inspire a tune from scratch by providing a set of initial chords in an unexplored key. With the onboard bank of 1,728 scales and modes including genre and artist presets, there’s more than enough to keep the juices flowing.

Once you’ve determined a scale, Scaler lays out basic diatonic chords for you to audition, and lets you take things further with dozens of chord variations and voicings to try out. Theory buffs can also get an insight into each chord’s harmonic function.

Ready to put together a progression? Simply drag and drop chords into Scaler’s sequencer, change up octaves and inversions, and record or drag the progression into your DAW.

Download and Installation
This is a straightforward process, the file is quite small so download and installation is quick. Registration is similarly straightforward. When you have purchased Scaler it is available to download from the ‘My Products’ section of your account where you will find a keyfile to download. When you lauch Scaler, you register the keyfile and enter your registered email address and you’re good to go.

It’s worth noting that there are two versions, Scaler and ScalerControl. They are essentially the same except ScalerControl is designed for DAWs that use AU plugins that don’t allow you to route midi to other tracks.

It’s also worth checking the website because there are some compatibility issues although these are being fixed as Scaler is updated. In version 1.2 the reported issues are that Maschine 2 and Reason don’t support midi routing.

Using Scaler
Scaler effectively has 3 modes. It can detect chords and identify what key / scale you are playing, you can explore a range of keys and scales and you can create your own chord progressions.

Scaler loads as a midi effect. In Usine Sensomusic Hollyhock 3 you simply need to load Scaler as a patch into a rack and load the VST synth you want to control underneath. You can load the pianoroll between the two to drag and drop the chords / progressions onto.

In MuLab 7 it’s a very similar process, load Scaler into a rack and load the VST synth you want to control underneath. You then drag and drop the progression / chords onto the track for the Scaler rack.

Since I wrote the original review, there have been two updates and the current version is 1.2.1. This brings a number of improvements and bug fixes.

The GUI is clean and well laid out. The top section has the control bar with a display for the input note / chord, help, volume and sound selection, tooltips and embedded guide and global settings. The keyboard underneath acts as an input device and display for notes in a selected scale.


Beneath this is the option to turn on midi detect and the chord set selector that you can choose between song type, artist or user set. When you choose a song or artist the chords are displayed underneath.


The next section shows detected scales including details of the number of matching notes and chords and mood of the particular scale. This can be expanded to include more details.


Beneath this is the chord selection and progression builder. When you select a song by style or artist, the chord progression is displayed in the top section of the GUI. The detected scales section shows the most appropriate scale and the chords in that particular scale are displayed at the bottom. The diatonic chords are the ‘basic’ chords and chord variations offers a range of different sounds and the voicings options allows you to play the notes in a different order which gives further variation. The display to the right shows the note, it’s relative position in the chosen scale and a couple of chord substitutions.


Often chords will fit more than one scale so if you highlight a different detected scale, the chords that fit are highlighted in blue on the progression shown in the top part of the display and as you scroll down the list and select these different scales you will see that fewer and fewer chords fit into that particular scale.

You can drag chords from the top section into the progression builder as suggested in the chord progression but you can also audition and select alternatives and different voicings from the selection options to fine tune the progression and create interest and variation. You can choose the octave and inversion and then play the progression.

The final stage is to drag the progresssion or individual chords into your DAW.

I think this is a very useful tool for musicians that don’t know music theory but also for those that do. For those with a limited knowledge, it could be useful to identify what chords you are using and help you sound more musical by choosing chords within a particular key or scale. If you know music theory, it could help you identify substitute chords, create new progressions from styles you might not normally use.

Either way it is a tool to provide inspiration and help you find new ways to be creative. There is a focus on modern music styles with a number of artists and progressions that are difficult to find generally so it’s an excellent tool to help you create new styles of music that you may struggle to do on your own.

It’s great that the developers have implemented a number of improvements and have established a user community. A lot of comments that I was going to make have already been addressed in recent updates.

The included scale set has been increased from major, minor, all the modes plus altered, harmonic major / minor and pentatonic major / minor to include 11 new scales – Lydian augmented scale; Acoustic scale; Major locrian scale; Ukrainian dorian scale; Hungarian gipsy scale; Melodic minor scale (asc); Half-diminished scale; Phrygian dominant scale; Persian scale; Neapolitan major scale; Neapolitan minor scale; Other. These contain some more unusual / exotic scales and are a great inclusion to providing a very wide scope for creativity.

There are a couple of other updates that make Scaler more usuable. There is an option to randomise velocities giving chords a more natural sound, the chord progression builder has been increased from 8 to 16 chords and you can now specify the chord length when you export as midi. The length is the same for all chords so if you using a number of different chord lengths it may be easier to export individual chords and edit them rather than the whole progression.

Although Scaler has an excellent set of chord progressions, I’d say that you need to think about how to change these to keep interest and add variation over time, you also need to think about basslines and melodies to create a whole song for example. That’s more of a challenge if you don’t know music theory. A suggestion for future updates would be tools to create such melodies and basslines, especially for some of the modern EDM styles. Maybe this is going above and beyond towards software like RapidComposer which I’ve previously reviewed. This allows you to create an entire song including chords, basslines, melodies, piano lines, strings and you can export these as midi files. There is a much steeper learning curve and it doesn’t have the same depth of modern chord progressions, however.

If you’re looking for a tool that you can pretty much use straightaway, is quick and easy and provides inspiration for many modern music styles then Scaler is a very good option. If you’re looking for more of a compositional tool then Scaler isn’t really suited to this but it can give you a great start.

I’ve used the original version of Scaler several times on ‘oblique coherence’ embedded above.

‘so called progress leaves me cold’ was created using Scaler to create the chord progression, 5 instances of SampleScience Player processed using SphereDelay, Blackhole (Eventide), mini filter V (Arturia), Cryogen (Glitchmachines) and SphereDelay. I’ve also used a sample from Urban and Suburban sample pack from Boom Library.

‘oblique coherence’, ‘bricks’ and ‘posters’ were recorded live in Usine Sensomusic Hollyhock 3. The chord progressions were created in Scaler and I’ve used SampleScience Player with SphereDelay and SpecOps (Unfiltered Audio); Synthmaster 2 (KV331 Audio) with SphereDelay and Blackhole. I’ve recorded quotes from YokoOnoBot on twitter processed in the joggle sampler with SphereDelay and also processed in the Grain MicroLoop sampler (using automation of speed and gain parameters) with SphereDelay. I’ve also used Type A (AudioThing) and Litote (Inear Display) with automation on the master channel.

‘disengage’ was created using 3 instances of SampleScience player processed with SphereDelay and Blackhole. Samples from the biomorph pack by Glitchmanchines were processed with SphereDelay and Blackhole.

‘fractured memories haunt my dreams’ was created using RapidComposer and four instances of SampleScience Player processed with SphereDelay, Blackhole and Octavox. The chord track was duplicated and processed with SpecOps.

‘drawn to the stars’ was created using RapidComposer and five instances of SampleScience Player processed with SphereDelay and Blackhole.

‘old houses’ was created using RapidComposer and six instances of SampleScience Player processed with Blackhole, SphereDelay and Octavox.

‘affirmation’ was created using Scaler for the chord progression, Synthmaster One processed with SphereDelay and Blackhole, three instances of SubBoomBass2, one processed with SphereDelay. A background sample from the Urban and Suburban sample pack by Boom Library.

All songs mastered using Ultrachannel (Eventide), Magnetite (Black Rooster Audio), Elevate (Newfangled Audio) and Stage (Fiedler Audio).