spool.

MIDI

Play spool. like hardware by connecting an external MIDI controller. MIDI input is a Spool Pro feature.

USB MIDI

Connect a class-compliant USB MIDI keyboard or controller through a USB-C or Lightning adapter and spool. picks it up automatically — your keys play the current sound, with velocity. Controllers are hot-plug aware: connect and disconnect whenever, mid-session.

Bluetooth MIDI

Open the MIDI settings (piano icon in the top bar) and tap Bluetooth MIDI… to pair through the system’s Bluetooth MIDI screen. Once paired, it behaves exactly like a USB controller. The settings screen also shows a live last activity readout so you can confirm notes are arriving.

What MIDI controls

  • Notes and velocity play the current synth or drum sound.
  • Control-change (CC) messages can drive spool.’s knobs from your hardware.

Coming later

  • External clock sync (following another device’s MIDI clock) is on the tempo screen as coming soon — spool.’s internal clock is the boss for now.
  • An AUv3 plugin version of spool. — running inside other iOS music apps — is planned for a future update.

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