---
title: KeyResult.KeySignature
framework: musicunderstanding
role: symbol
role_heading: Structure
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, macOS 27.0+, tvOS 27.0+, visionOS 27.0+, watchOS 27.0+]
path: musicunderstanding/keyresult/keysignature
---

# KeyResult.KeySignature

The set of sharp and flat symbols for the notes.

## Declaration

```swift
struct KeySignature
```

## Overview

Overview A key signature pairs a root note, tonic with a mode, major or minor, to describe the harmonic center of a section of audio.

## Topics

### Tonic and mode

- [tonic](musicunderstanding/keyresult/keysignature/tonic.md)
- [mode](musicunderstanding/keyresult/keysignature/mode.md)

## Relationships

### Conforms To

- [Decodable](swift/decodable.md)
- [Encodable](swift/encodable.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Getting the notes of a key

- [tonic](musicunderstanding/keyresult/keysignature/tonic.md)