# Key Change — Music modulate key change

> Music theory app for key modulation and chord transitions. (iPhone/iPad app by William Ooms.)

- Source: https://appshunter.io/ios/app/key-change/id1410864507 (this page in markdown: same URL + `.md`)
- Developer: [William Ooms](https://appshunter.io/developer/1396572145)
- Category: Music, Education
- Price: $0.99
- Rating: 1.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 12.0 · 15 MB
- Languages: American English
- Released: 2018-10-11
- Data updated: 2026-06-24
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/key-change/id1410864507/reviews.md

## What is Key Change?

For pianists, organists, and other musicians: This app shows how to modulate from one key to another key with a few simple chords. Simply select the original key signature and the new key signature. You will see the chords to play in the score window. Major and minor keys are supported. At the bottom of the screen are the chord names and a brief description of the chord's relationship to the original key and the new key. Swipe sideways over the score to hear the chords being played. The transition chords may be shown in various inversions by swiping up or down over the chord.

The chords are generated based on the simple rules that were used by Carlos Salzedo and Lucile Lawrence in there book "The Art of Modulating" printed in 1950. Although this fine book is still in print, it is difficult to carry the book with you. No need to scan through hundreds of examples from the book when one app on your phone or tablet can generate you what you want instantly.

## Key features

- Key signature selection
- Chord generation for modulation
- Major and minor key support
- Chord name and description display
- Audio playback of chords
- Chord inversion exploration


## Frequently asked questions about Key Change

### What is Key Change used for?

Key Change is a music theory tool designed to help musicians understand and practice modulating from one key signature to another. It displays the necessary chords and their relationships to both the original and new keys.

### What keys does Key Change support?

Key Change supports both major and minor keys. You can select any original key signature and any new key signature to see the transition chords.

### Can I hear the chords in Key Change?

Yes, you can hear the chords being played by swiping sideways over the score window. This feature allows you to audibly experience the chord transitions.

### How does Key Change generate chords?

The chords are generated based on the simple rules outlined in the 1950 book "The Art of Modulating" by Carlos Salzedo and Lucile Lawrence. This app provides instant access to these principles without needing the physical book.

### What devices is Key Change available on?

Key Change is available on iPhone, iPad, and iPod. It is designed for mobile and tablet use.

### How often is Key Change updated?

The latest version of Key Change is 1.0.1, which was last updated on April 29, 2021. It was originally released on October 11, 2018.

### What is the price of Key Change?

Key Change is a paid application, priced at $0.99. There are no in-app purchases or subscriptions required.

### Does Key Change have ads?

No, Key Change does not contain advertisements. It is a completely ad-free application.

## Version history (last 2 releases)

### 1.0.1 — 2021-04-29

Fixed issues with dark mode appearance. Recompiled with Xcode 12.5.

### 1.0 — 2018-10-10

No release notes.

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## More apps by William Ooms

- [HarpPedals](https://appshunter.io/ios/app/harppedals/id1396572146)
- [Hand And Foot Canasta](https://appshunter.io/ios/app/hand-and-foot-canasta/id1397085033)
- [Pickleball Referee Timer](https://appshunter.io/ios/app/pickleball-referee-timer/id1574246067)

All apps by William Ooms: https://appshunter.io/developer/1396572145

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-24.*