---
title: scheduleMIDIEventBlock
framework: audiotoolbox
role: symbol
role_heading: Instance Property
path: audiotoolbox/auaudiounit/schedulemidieventblock
---

# scheduleMIDIEventBlock

A block used to schedule MIDI events.

## Declaration

```swift
var scheduleMIDIEventBlock: AUScheduleMIDIEventBlock? { get }
```

## Discussion

Discussion As with the render block, a host should fetch this block before beginning to render, if it intends to schedule MIDI events. This property is implemented in the AUAudioUnit base class. If the audio unit is not a music device or effect, this property is nil. Subclasses should not override this property. When hosts schedule events via this block, they are delivered to the audio unit via the list of render events delivered to the internalRenderBlock implementation.

## See Also

### Managing MIDI Events

- [isMusicDeviceOrEffect](audiotoolbox/auaudiounit/ismusicdeviceoreffect.md)
- [virtualMIDICableCount](audiotoolbox/auaudiounit/virtualmidicablecount.md)
- [midiOutputEventBlock](audiotoolbox/auaudiounit/midioutputeventblock.md)
- [midiOutputNames](audiotoolbox/auaudiounit/midioutputnames.md)
- [AUScheduleMIDIEventBlock](audiotoolbox/auschedulemidieventblock.md)
- [AUMIDIOutputEventBlock](audiotoolbox/aumidioutputeventblock.md)