The iPad is, on paper, an excellent MPE machine. It has a USB-C port that class-compliant controllers plug straight into, a large catalogue of AUv3 instruments, and no driver installation to speak of. In practice, people connect a LinnStrument or a ROLI Seaboard to an iPad, load a synth, and get monophonic pitch bend smearing across the whole chord.
The problem is almost never the controller or the synth. It is a link in the middle that collapses 16 channels down to one.
Why iPad MPE breaks differently than desktop MPE
MPE works by giving every held note its own MIDI channel, so that pitch bend, pressure and CC74 apply to that note alone. A conventional MIDI routing setup assumes the opposite: that a channel identifies an instrument, and that several apps can share one port by listening on different channels.
Those two models are incompatible. This is the single most important rule of iPad MPE: in MPE mode, one instrument needs one entire MIDI port, because MPE consumes all 16 channels of it. You cannot put two MPE synths on one virtual port and separate them by channel. If you want two expressive instruments, you need two ports.
Almost every "my iPad won't do MPE" thread comes back to this.
Hosts
AUM is the default recommendation, and deservedly so — but it is also where the confusion lives. AUM has an explicit MPE mode on its MIDI inputs, toggled from the channel button in the upper left, separate from a Filter Multichannel mode. The distinction matters most when recording: MPE mode routes the full multi-channel stream to one destination, whereas multichannel filtering is what you want when several single-channel sequencers are feeding different tracks. Pick the wrong one and your expression data either vanishes or arrives on the wrong instrument.
Drambo handles MPE natively and, because it is modular, lets you unpack the per-note streams and route pressure or slide anywhere you like inside a patch. It also runs as an AUv3 inside another host, which makes it a useful MPE processing block rather than just a destination.
Loopy Pro and Cubasis both host AUv3 instruments and can carry MPE, but both need deliberate routing rather than default settings. In Cubasis in particular, getting a full 16-channel stream onto a single track usually means being explicit about virtual MIDI ports and channel assignment rather than trusting the automatic setup.
GarageBand remains the weak link. It is fine as a sketchpad, but it is not the tool to reach for if per-note expression is the point of the session.
A rule of thumb for testing your chain
Before blaming a synth, isolate the layers:
- Controller → host. Play a held note and bend a second note. If the host's MIDI monitor shows both notes on the same channel, the problem is upstream of the instrument.
- Host → instrument. Confirm the instrument's own MPE switch is on. Many AUv3 synths default to off, and a few require a matching pitch-bend range setting.
- Bend range. The classic silent failure: the controller sends ±48 semitones, the synth expects ±2, and everything sounds subtly wrong rather than obviously broken.
Apps worth knowing about
A few iPad tools exist specifically to make expressive playing work:
- MPEdie is a free MPE controller that runs standalone and as an AUv3 MIDI plugin inside AUM, Drambo or Loopy Pro — which means you can generate MPE inside the host without any hardware at all. It is the cheapest possible way to find out whether your chain passes expression correctly.
- MIDI Tape Recorder from Uwyn captures raw MIDI including the full MPE stream, which is invaluable when you want to keep a performance exactly as played rather than as your host chose to quantise it.
- DiscoDSP Bliss on iPadOS offers native MPE with independent per-note pitch bend, CC74 timbre and pressure mapping, and is a good test instrument precisely because its MPE implementation is explicit rather than implied.
Practical setup that works
For a straightforward expressive rig: controller into the iPad over USB-C, AUM as the host, MPE mode enabled on that input, one destination instrument per MIDI port, and the instrument's own MPE switch confirmed on with a bend range matching the controller. Add Drambo as an AUv3 if you want to reshape pressure curves on the way in. Record with MIDI Tape Recorder if the performance is the deliverable.
That chain is reliable. Most of the alternatives are too, as long as you respect the one-port-per-instrument rule and stop expecting channel filtering to coexist with MPE.
The honest caveat
iPad MPE is very good once configured, but it is configuration-sensitive in a way desktop DAWs increasingly are not. On a desktop, MPE has largely become a checkbox. On iOS, you are still assembling the routing yourself — a fair trade for a rig that fits in a bag and boots instantly, but worth sorting out before a gig rather than during one.