How do you connect a MIDI controller to an iPhone or iPad?
Plug a class-compliant USB MIDI controller into the USB-C port (or into Apple's Lightning to USB 3 Camera Adapter on older devices), or pair a Bluetooth MIDI controller from inside a music app. Then turn on MIDI input in the app, pick the track you want to play, and play. Keyboards play notes; pad controllers usually map to drum pads starting at MIDI note 36.
What You Need
- An iPhone or iPad with a USB-C port, or a Lightning device plus Apple's Lightning to USB 3 Camera Adapter
- A class-compliant MIDI controller (most current models from Akai, Novation, Arturia, and Korg are)
- A music app with MIDI input
- Optionally, a powered USB hub if your controller draws more power than the phone supplies
Step 1: Choose USB or Bluetooth
USB is the most reliable option and has the lowest latency. Most small keyboards and pad controllers work over USB with no driver, because iOS supports class-compliant MIDI.
Bluetooth MIDI (BLE MIDI) removes the cable. Controllers like the Korg nanoKEY Studio, and keyboards with built-in Bluetooth MIDI, pair this way. Expect a little more latency than USB, which matters most for fast drumming.
Step 2: Connect the Controller
For USB, plug the controller in. If it doesn't light up, it needs more power than the device provides. Connect it through a powered USB hub, or use the camera adapter's extra power port on Lightning devices.
For Bluetooth, don't pair from iOS Settings: MIDI devices usually won't show up there. Open the Bluetooth MIDI option inside your music app instead, which uses Apple's built-in MIDI pairing screen.
Step 3: Turn On MIDI Input in Your App
Many apps keep MIDI input off until you enable it, so the controller doesn't trigger sounds by accident. Look in the app's settings for a MIDI section, enable input, and check that your controller appears in the device list.
You may also see an entry called Network MIDI or Session 1. That's Apple's built-in network MIDI session, used to send MIDI from a Mac over Wi-Fi. It's safe to ignore.
Step 4: Set the MIDI Channel
Omni (all channels) is the simplest setting and works for one controller. Choose a single channel if you have more than one MIDI device connected, or if your controller sends on a fixed channel and you want the app to ignore everything else.
Step 5: Map Pads to Drums
Keyboards map naturally: each key sends its pitch. Pad controllers need to line up with the app's drum pads. Most apps map consecutive MIDI notes to pads starting at a base note, and the General MIDI convention starts drums at note 36 (C1 or C2, depending on the app's octave naming). If your first pad triggers the wrong sound, change the base note in the app or the note your controller sends.
Step 6: Select a Track and Play
MIDI usually plays whichever track is selected in the app. Pick the track first, switch the app to the right mode (notes, drums, or sampler), then play. To record, arm the track and start playback, the same as when tapping on screen.
Troubleshooting
| Problem | Likely cause | Fix |
|---|---|---|
| Controller doesn't power on | Not enough bus power | Use a powered USB hub |
| Lights up but no sound | MIDI input is off in the app, or the wrong channel | Enable input; set channel to Omni |
| Wrong drum sounds | Base note mismatch | Adjust the pad base note |
| Notes lag behind | Bluetooth MIDI or Bluetooth headphones | Use USB, and wired headphones |
| Works until you switch apps | iOS suspends audio apps in the background | Keep the music app in the foreground |
Using a MIDI Controller with ARC-24
ARC-24 takes MIDI input from USB or Bluetooth controllers. It's off by default. Open Setup → MIDI and turn on Enable MIDI Input. USB controllers appear as soon as they're connected, and Bluetooth MIDI opens Apple's pairing screen. ARC-24 connects to every available source automatically while input is on.
What each mode does with MIDI:
- Notes plays each key's pitch on the selected synth track with velocity. Hold and the arpeggiator respond to MIDI the same way they respond to pad taps.
- Drums maps consecutive notes to kit pads from the Pad Base Note (default 36). The mapping is chromatic, so white keys alone skip pads. Setup shows the full note range the current kit needs.
- Sampler uses the same base note for the sixteen pads. In Keys layout, notes play the source sample pitched.
Channel can be Omni or a single channel from 1 to 16. MIDI settings are global, so your mapping carries across every song. Chords mode doesn't take MIDI yet.
ARC-24 has eight tracks for synths, samples, and drums, a 7-day free trial, and a one-time unlock ($9.99 USD on the US App Store, varies by region).
FAQ
Do I need an adapter to connect a MIDI keyboard to my iPhone?
On iPhones and iPads with USB-C, a USB-C cable or a USB-A to USB-C adapter is enough. On Lightning devices, use Apple's Lightning to USB 3 Camera Adapter, which also has a port for external power.
Why won't my MIDI controller turn on when connected to my iPhone?
The controller needs more power than the phone supplies. Connect it through a powered USB hub, or through the camera adapter with its power port connected.
Do Bluetooth MIDI controllers work with iPhone?
Yes. Pair them from inside a music app's Bluetooth MIDI screen rather than from iOS Settings, where they usually don't appear.
Can I play iPhone synth apps like a real instrument?
Yes. A MIDI keyboard gives you velocity-sensitive keys, which most iOS synths respond to with louder or brighter notes. It feels much closer to playing hardware than tapping glass.
What MIDI note do drum pads start on?
General MIDI drums start at note 36, and many apps use that as the default base note for pad mapping. Your app or controller may let you change it.