Ableton Live 12's MIDI Generators, explained

MIDI Generators are one of Live 12's Generative Tools: unlike a Transformation, which reshapes notes you've already written, a Generator adds brand-new notes to a clip from scratch, based on the parameters you set. Live 12 has four native Generators — Rhythm, Seed, Shape and Stacks — plus Euclidean, a bundled Max for Live Generator. All five are scale-aware and available in Live 12 Standard and Suite, not Intro.

This guide covers what each Generator does and its key parameters, using the companion video below (which also covers MIDI Transformations — see that guide for those).

What you need

Unlike Meld, Roar and Granulator III, which are Suite-exclusive, MIDI Generators ship in Standard too. Only Intro misses out.

How Generators work, in general

Open a clip, switch to the Generate panel, and pick a Generator from the chooser, as the MIDI Tools chapter of the Live 12 manual documents in full. With Auto Apply on (the default), notes appear in the clip immediately as you adjust parameters. Turn Auto Apply off to fine-tune settings first, then press Apply (or Ctrl/Cmd+Enter) when you're happy.

Generators act on the current time selection, or the whole clip loop if there's no time selection. If the clip already has notes, generated notes that overlap the existing ones replace them; notes that don't overlap are added alongside. The Reset button restores a Generator's own parameters to default — it doesn't touch notes already in the clip, and generating and regenerating notes can still be undone with Undo from the Edit menu.

If a clip has an active scale, every pitch-related parameter in a Generator — pitch ranges, chord roots, and so on — works in scale degrees instead of semitones, and stays inside that scale automatically.

Rhythm

Rhythm builds a repeating note pattern for a single pitch or Drum Rack pad — the tool to reach for when you want a beat or a rhythmic sequence without programming each hit by hand.

• Steps sets the pattern length, up to 16 steps; Pattern picks the shape of the pattern (which steps have notes), and the number of available patterns depends on Steps and Density (how many notes are in the pattern).
• Step Duration controls how often the pattern repeats within your time selection — for a one-bar selection with 8 Steps, a Step Duration of 1/8 repeats the pattern once, while 1/16 repeats it twice.
• Split adds a probability that any given step divides in two; Shift moves the whole pattern earlier or later by a number of steps.
• Velocity and Accent set two velocity levels, and Accent Frequency controls how often an accented note occurs.

To build a full drum pattern, generate one pitch or pad at a time: deselect the notes Rhythm just created, pick a new pitch or pad, and adjust its settings for a second pass.

Seed

Seed randomly generates notes inside pitch, duration and velocity ranges you define — useful for sketching a MIDI idea fast, or adding controlled randomness to a part.

• Pitch Range, Duration Range and Velocity Range sliders (or handles) set the bounds for each. Merge the two Pitch Range handles together to generate notes on a single pitch only.
• Voices sets the maximum number of notes that can sound at once; Density sets how much of the pitch range gets populated with notes, as a percentage.

Shape

Shape distributes notes along a melodic contour — draw your own shape or pick a preset, and Live fills it with notes inside a pitch range.

• Draw a custom curve in the display, or choose one of the Shape Presets.
• Minimum and Maximum Pitch bound the range notes are generated in.
• Rate sets the minimum note length, and Tie sets the probability that a note extends into the next one.
• Density sets how much of the shape gets populated with notes.
• Jitter randomizes generated pitches away from the exact shape — at 0% notes sit exactly on the curve, and higher values wander further from it while staying inside the pitch range.

Stacks

Stacks generates chords and chord progressions from a Tonnetz-based chord selector, entirely within a scale — the fastest way to sketch harmony without knowing music theory by hand.

• Chord Selector Pad: drag or use Ctrl/Cmd + arrow keys to pick a chord pattern; hovering shows the chord's details in the status bar.
• Add Chord / Delete Chord build a progression out of multiple chords in sequence.
• Chord Root sets the chord's root note. With a clip scale active, the root automatically defaults to the scale's root, though you can still pick any other note within that scale.
• Chord Inversion cycles through inversions; Chord Duration and Offset set each chord's length and position, in eighths of the original chord length.
• Custom chord banks: Stacks can load your own chord sets from .stacks files (JSON), placed in a Places folder in the browser — useful if you want a specific, repeatable set of voicings across projects.

Euclidean

Euclidean is a bundled Max for Live Generator (not a native Live device) that builds Euclidean rhythms — evenly-distributed hit patterns — for up to four independent voices at once.

• The Pattern tab visualizes the rhythm and lets you toggle each voice on/off and set a Rotation offset per voice (or randomize all of them at once).
• The Voices tab assigns each voice its own pitch or Drum Rack pad, plus an independent Velocity.
• Steps sets pattern length, Density sets how many times it repeats within the selection, and Division sets the length of a single step.

Because it's Max for Live rather than a native device, Euclidean (like Velocity Shaper, the equivalent Max for Live Transformation) can be edited or rebuilt in a Max patcher if you want to go further than its interface exposes.

Frequently asked questions

Are MIDI Generators available in Ableton Live Standard?

Yes. Rhythm, Seed, Shape and Stacks are available in both Live 12 Standard and Suite — only Intro misses them. That's different from Suite-exclusive Live 12 devices like Meld, Roar and Granulator III.

What's the difference between a Generator and a Transformation?

A Generator creates new notes from scratch, based on its own parameters, and can replace existing overlapping notes. A Transformation reshapes notes you've already selected — it needs existing notes as input. See the MIDI Transformations guide for the Transform-side tools.

Is the Euclidean Generator a native Live device?

No. Euclidean is a bundled Max for Live MIDI Tool, one of two included with Live Standard and Suite (the other is the Velocity Shaper Transformation). It's still installed by default — you don't need to build or download anything to use it.

Do MIDI Generators follow Live's scale settings?

Yes. All MIDI Tools, including every Generator, are scale-aware. When a clip has an active scale, pitch parameters work in scale degrees instead of semitones, and Stacks' chord root defaults to the scale's root note.

Will a Generator overwrite notes already in my clip?

Only where the generated and existing notes overlap in time — those get replaced. Notes that don't overlap are added alongside what's already there.

Which Generator is best for chord progressions?

Stacks, which is built specifically for chords: it generates single chords or full progressions from a Tonnetz-based chord selector, follows the clip's scale automatically, and supports custom chord banks for repeatable voicings.