Ableton's Add Interval Fix, and Octave-Doubling Your Bass

October 16, 20266 min read

A Quiet Fix Buried in Yesterday's Beta

Ableton pushed Live 12.4.15b7 on October 15, 2026, and if you only skim the headline bullet (some interface text updates), it looks like a nothing release. It isn't. Tucked under "Bugfixes" are three changes to how MIDI note duplication interacts with Transformations, and the third one is the interesting one for anyone who builds basslines out of layered notes instead of layered devices:

Duplicating notes and then running a Transformation now creates its own separate undo step, instead of getting bundled into one messy undo action.
Duplicated notes no longer get assigned duplicate note IDs under the hood.
Using Add Interval no longer drops the base notes of the duplicated content.

That last one is the actual workflow fix. If you've never used Add Interval, this is also as good a reason as any to start.

What Add Interval Actually Does

Add Interval lives in a part of the piano roll most producers never open: the Pitch and Time Utilities panel, under Pitch Tools, right next to Transpose, Fit to Scale, and Invert. It's easy to miss because it doesn't look like a "feature" — it's a slider (Interval Size) and a button (Add Interval) sitting below the more obvious Transpose control.

Here's the distinction that matters: Transpose moves the notes you've selected. Add Interval adds new notes at a distance from the ones you've selected, without touching the originals. Set Interval Size to 12 and hit Add Interval, and every selected note gets a duplicate sitting exactly an octave above it — and the notes you started with are still there, untouched, sitting underneath.

That's a non-destructive doubling tool built directly into the MIDI editor, with no need to duplicate a track, no second instrument slot, and no copy-paste-transpose dance.

One detail worth knowing before you touch it: Interval Size is measured in semitones by default, but if the clip has an active scale set, it switches to scale degrees instead. Set the clip's scale to match your key, and an Interval Size of 7 won't add a fixed interval — it'll add whatever note sits seven scale degrees away, which for a bassline under moving chords is usually a more musically useful fifth or sixth than a mechanically identical interval would be.

The Bass Use Case: Instant Octave and Fifth Stacks

This is where it gets genuinely useful for low end specifically, not just MIDI editing in general.

Take a programmed bassline — root notes only, nothing fancy. Select all the notes, set Interval Size to 12, hit Add Interval. You now have the same bassline doubled an octave up, sitting in the same clip, on the same track, hitting the same instrument. Depending on what's loaded, that's an instant way to:

Add upper-octave harmonic content for translation on small speakers, without reaching for a harmonic exciter or an Add Oscillator-style synth trick.
Build a two-voice bass patch (sub down low, a more defined tone an octave up) out of one monophonic instrument, as long as that instrument can handle polyphony on the stacked notes.
Stack a fifth (Interval Size 7 in semitones, or scale-degree-aware if a scale is set) under a chord-following bassline for a fuller, more harmonically active low end, instead of a flat root-only line.

The part that used to bite people: if you wanted to duplicate a phrase of bass notes and add an interval layer to the duplicate — a completely reasonable two-step workflow, duplicate the idea, then stack it — the base notes of that duplicated content could get silently dropped. You'd end up with only the interval layer surviving, not the original-plus-interval pair you were trying to build. That's exactly the bug 12.4.15b7 fixes.

Why the Note-ID and Undo Fixes Aren't Just Technical Trivia

The other two fixes in this beta round aren't cosmetic either, if you've been burned by them without realizing it.

Duplicate note IDs: Before this fix, duplicating notes could leave the copies sharing an identity with their source under the hood. In practice that's the kind of bug that shows up as weird, hard-to-explain behavior later — a Transformation or a Max for Live MIDI tool that tracks notes by ID affecting notes you didn't select, because Live quietly thought two different notes were the same one.

Separate undo steps: Before this fix, duplicating notes and then applying a Transformation could collapse into a single undo action. That's a real problem for exactly the Add Interval workflow above — if you duplicate a phrase, add an interval, don't like the stacked result, and hit undo expecting to just remove the interval layer, you could instead undo both steps at once and lose the duplicate too.

None of these are headline features. All three point the same direction: Ableton was cleaning up a specific, real workflow (duplicate → stack an interval → keep editing) that wasn't behaving reliably. If you'd tried this and quietly given up on it a few betas ago, it's worth another look now.

A Concrete Workflow to Try

Program or import your bassline into a MIDI clip, root notes only.
Select all notes (Cmd/Ctrl+A with the clip focused).
Open the Pitch and Time Utilities panel if it isn't already visible.
Set Interval Size to 12 for an octave stack, or 7 for a fifth.
Hit Add Interval. Check that your original notes are still there underneath the new layer — this is the exact thing that was broken before 12.4.15b7.
If the instrument on the track is monophonic, you'll need to either switch it to a polyphonic patch or split the stacked notes onto a second track/instrument to hear both layers at once.
Duplicate the whole clip before you experiment further — now that duplication and Add Interval play nicely together, it's a cheap way to compare the doubled version against the original without losing either.

Where It Still Falls Short

Add Interval doesn't check whether a new note collides with something already sitting at that pitch — it just adds the note, so overlapping layers can clash or double up if you run it more than once on overlapping selections. It also doesn't vary velocity between the original and added notes, so a stacked octave layer will play at the exact same velocity as its source, which can sound mechanical on a bassline that's supposed to breathe. You'll likely want to go in afterward and manually pull the velocity down on the added layer, especially if it's meant to sit as support rather than as an equal voice.

It's also strictly an editing tool, not a live/real-time device — there's no equivalent of this running on audio or on a held note inside something like Shifter or Auto Shift. If you want this kind of octave-stacking behavior on an audio bass signal rather than MIDI notes, those pitch-manipulation devices are still the right tool, not this one.

Takeaway

Add Interval has been sitting in Live's Pitch Tools panel for a while, quietly underused because it does something unglamorous: it duplicates notes at a set distance instead of moving them. The 12.4.15b7 beta fix means the obvious next step — duplicating a bass idea and layering an interval onto the copy — finally works the way you'd expect, with your original notes intact and undo behaving sanely. If octave-doubling or fifth-stacking your bass MIDI has always meant manual copy-paste-transpose, this is worth fifteen minutes to actually try.