Ableton shipped Live 12.4.5 on August 26, 2026 — a maintenance release with no headline features, the kind most people install without reading the notes. But scan back through the whole 12.4 cycle, which started with 12.4 on May 5, and a pattern emerges: MPE support in Live keeps getting incrementally repaired in places that only expressive players would ever notice.

None of these changes will make a launch video. Together they explain why Live feels less fiddly with an MPE controller than it did a year ago.

Ctrl-e now loads in MPE mode by default

The most concrete change came in 12.4.3 (July 14, 2026): MPE mode is now enabled by default for the Ctrl-e plug-in from Expressive E.

Ctrl-e is the free companion instrument Expressive E built for the Osmose CE, the controller-only version of its keyboard. If you loaded it in Live before this update, the track defaulted to standard MIDI mode and every one of the Osmose's expressive gestures collapsed into ordinary note-on velocity until you found the MPE toggle in the track's MIDI settings.

This is the single most common first-run failure for new MPE users in any DAW: the controller is fine, the plugin is fine, and the sound is flat because the track was never switched into MPE mode. Ableton hard-coding the correct default for a known MPE instrument is a small but meaningful acknowledgement that per-note should be the assumption, not the exception, when the plugin was built for it.

MPE Control device fixes

Two fixes in the 12.4 release itself targeted Live's own MPE Control device, which reshapes incoming expression data before it hits an instrument.

The first: MPE Control no longer sends out an initial CC 74 value when loaded. That stray CC 74 on load could jump a slide-mapped parameter to an arbitrary position the moment you dropped the device on a track — the sort of thing that makes you think a preset is broken when it isn't.

The second was cosmetic but irritating: the device would briefly expand and then snap back to standard size immediately after loading. An earlier fix in the same family stopped MPE Control from ceasing MIDI output when the curve min/max settings were continuously automated, which mattered for anyone modulating expression response over the course of a track.

Rendering and compatibility groundwork

Two more items from the 12.3 line are worth knowing about if you're only now updating.

Windows users got a substantial performance fix: the GPU renderer now handles curves such as MPE curves in the MIDI Note Editor with far less memory, which also reduces the audio glitches that the renderer could previously cause. MPE clips are dense — each note carries three continuous curves — and editing a busy passage was one of the reliable ways to make the editor stutter.

Separately, Live now shows Kilohearts Phase Plant, Multipass and Snap Heap as MPE-compatible in the browser. Live's browser flags which plugins accept per-note data, and a plugin that isn't flagged sends users hunting through manuals to find out whether it's worth wiring up. Phase Plant in particular has been a serious MPE instrument for years; having Live say so is overdue.

What to do with this

If you're on Live 12 with an expressive controller, three practical takeaways:

For a fuller picture of how Live handles per-note data, Ableton's own Editing MPE chapter in the Live 12 manual and its MPE in Live FAQ remain the clearest references.

The broader read: Ableton isn't marketing MPE improvements, it's maintaining them. After the initial wave of "we support MPE now" announcements across the DAW landscape, this second phase — fixing defaults, load behaviour and editor performance — is what actually determines whether expressive playing feels good day to day.

More information: Live 12 release notes · Ableton Live