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# MIDINotificationMessageID

The types of state changes the system supports.

```
enum MIDINotificationMessageID
```

## Topics

### Change Types

[`kMIDIMsgSetupChanged`](/documentation/CoreMIDI/MIDINotificationMessageID/msgSetupChanged)

Some aspect of the current MIDI setup changed.

[`kMIDIMsgObjectAdded`](/documentation/CoreMIDI/MIDINotificationMessageID/msgObjectAdded)

The system added a device, entity, or endpoint.

[`kMIDIMsgObjectRemoved`](/documentation/CoreMIDI/MIDINotificationMessageID/msgObjectRemoved)

The system removed a device, entity, or endpoint.

[`kMIDIMsgPropertyChanged`](/documentation/CoreMIDI/MIDINotificationMessageID/msgPropertyChanged)

An object’s property value changed.

[`kMIDIMsgThruConnectionsChanged`](/documentation/CoreMIDI/MIDINotificationMessageID/msgThruConnectionsChanged)

The system created or disposed of a persistent MIDI Thru connection.

[`kMIDIMsgSerialPortOwnerChanged`](/documentation/CoreMIDI/MIDINotificationMessageID/msgSerialPortOwnerChanged)

The system changed a serial port owner.

[`kMIDIMsgIOError`](/documentation/CoreMIDI/MIDINotificationMessageID/msgIOError)

A driver I/O error occurred.

## Relationships

### Conforms To

[`Sendable`](/documentation/Swift/Sendable)

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Equatable`](/documentation/Swift/Equatable)

[`Hashable`](/documentation/Swift/Hashable)

---

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