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# scheduleMIDIEventBlock

A block used to schedule MIDI events.

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

## 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`](/documentation/AudioToolbox/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`](/documentation/AudioToolbox/AUAudioUnit/internalRenderBlock) implementation.

---

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