---
title: MIDINotification
framework: coremidi
role: symbol
role_heading: Structure
path: coremidi/midinotification
---

# MIDINotification

A message that describes a system state change.

## Declaration

```swift
struct MIDINotification
```

## Topics

### Inspecting the Notification

- [MIDINotificationMessageID](coremidi/midinotificationmessageid.md)
- [messageID](coremidi/midinotification/messageid.md)
- [messageSize](coremidi/midinotification/messagesize.md)

### Initializers

- [init()](coremidi/midinotification/init().md)
- [init(messageID:messageSize:)](coremidi/midinotification/init(messageid:messagesize:).md)

## Relationships

### Conforms To

- [BitwiseCopyable](swift/bitwisecopyable.md)
- [Sendable](swift/sendable.md)

## See Also

### Callbacks

- [MIDINotifyProc](coremidi/midinotifyproc.md)