Whether you’re a music theory novice in need of assistance with programming musically meaningful MIDI parts, or a seasoned composer looking for a purpose-built system with which to turn harmonic and melodic ideas into fully fledged phrases and sequences, there are plenty of superb software options available to help you out. Here are some of our favourites…

Your DAW And Other Tools

Before we get into our selection of plugins dedicated to composition assistance, we should point out that it’s likely that you already have access to a few such systems via your DAW and/or other plugins. Studio One’s Chord Track, for example, lets you play around with the harmonic structure and progression of a song on the fly, and works with both MIDI and audio. Other DAWs offer similar facilities, but none are as impressive as Studio One’s.

Then there are instrument plugins with built in automatic MIDI generators, including a number of libraries for Native Instruments Kontakt, and Toontrack EZdrummer 3, which introduces the amazing Bandmate. This ‘intelligent’ algorithm that literally creates a drum part for you to go with any imported MIDI or audio file, and while it has to be noted that conjuring realistic beats from thin air is far less complex than doing the same for chords and melodies, as an indication of how effective such machinery can be in general, it’s hugely exciting.

With all that said, then, let’s check out some of the finest MIDI-making plugins on the market.

Mixed In Key Captain Plugins

Mixed In Key’s weirdly named quintet of plugins comprises Captain Chords, Melody, Deep, Beat and Play, and while the last two are just a drum machine and simple chord generator, the other three comprise quite possibly the most comprehensive MIDI composition suite money can currently buy.

It all starts with Captain Chords, in which limitless chord progressions can be defined using key/scale-contextual chord palettes and rhythms, then edited in as little or much detail as you like. Captain Deep and Melody then connect to Captain Chords, tracking its structure and throwing out adherent basslines and lead parts that always make sense and sound great. You can preview your Captain Plugins compositions using the vast and genuinely high-quality onboard sound library built into each plugin, and, of course, all generated MIDI is easily exported to the host DAW.

There’s a bit of a learning curve to the pivotal Captain Chords, and a few workflow quirks to get used to, but this really is an incredible set of tools for any MIDI-based producer.

Plugin Boutique Scaler 2

It might not be pretty, but the coldly functional control panel of Plugin Boutique’s popular “music theory workstation” fronts a spectacularly powerful plugin for building chord progressions. Start by setting your key/scale, then drag chords from a palette of those available to that key/scale (including selectable Shapes, Voicings and Variations) to the Pattern panel to lay out your progression. Alternatively, there’s audio/MIDI scale detection and analysis, as well as hundreds of prefab chord sets, and more than 200 performance patterns are onboard for bringing rhythm to your chords.

That’s only the start of your harmonic adventure with Scaler 2, however, as the plugin opens up an astonishing amount of customisation and control, including arp and strum playback modes, live performance of chords, a very clever modulation guide, the ability to generate bass and lead lines based on the chords, and more. You also get a decent set of auditioning sounds.

Once you’ve accustomed yourself to its workflow, Scaler 2 proves itself as a go-to plugin for writing chord progressions from scratch, and making existing ones more interesting.

Xfer Records Cthulhu

Appearing at first to be a straightforward chord generator (press a single key, get a chord) and arpeggiator, Cthulhu soon reveals its cyclopean potential as a far more empowering compositional aid. Up to 128 chords (preset and/or user-specified, imported or recorded) can be assigned to individual MIDI notes for playing and sequencing, while the arpeggiator really qualifies as a creative step sequencer with its grid-style interface and wealth of per-step options, including note selection from within the chord, transposition, gate time, velocity and randomisation.

A versatile, transformative MIDI composition plugin at a great price. Check out our Show And Tell Review Of Cthulhu here.

AudioModern ChordJam, Riffer and PlayBeat

AudioModern’s trio of bright and friendly MIDI plugins employ user-guided randomisation to belt out an infinite continuum of endlessly varying chord sequences, melodies and electronic beats.

With your key and scale selected (or analysed from a dragged-in audio or MIDI file), ChordJam summons chords of up to five voices from single-note input, with independent control over the octave transposition, velocity and time offset of each, and the option of randomising them at a click or with every incoming MIDI note, constrained to within set ranges if required. It also features an arpeggiator, and a sequencer for stringing together chords of your own specification or randomly selected from a chosen pool.

Riffer pulls off similar MIDI-wrangling stunts to create musically legitimate, scale-locked melodies and sequences, with control over and randomising of note pitch, velocity, length and repeats (up to eight per step). Its four independent engines also enable polyphonic and polyrhythmic programming.

And PlayBeat applies the same approach as its stablemates to drums, randomising steps, pitch, flams, note repeats and more to come up with ever-shifting beats and grooves of up to eight parts. The latest version, PlayBeat 3.1, draws on the company’s new SMART algorithm to adapt its patterns to your personal rhythmic proclivities based on earmarked presets within your library, and we can only assume this will be making its way to the rest of the catalogue in the near future.

With creative randomisation firmly at the top of the collective agenda, ChordJam, Riffer and Playbeat are a lot of fun to work with and make for an endlessly inspiring set of MIDI generators. They’re all available on iPad, too.

Are you already using any of the plugins in our list, or do you have another MIDI generator to share with the group? Let us know in the comments.