# Circle of Fifths, Opus 2 — Advanced music theory - modes

> Interactive music theory tool for modes and jazz improvisation. (iPhone/iPad app by Felt Tip Inc..)

- Source: https://appshunter.io/ios/app/circle-of-fifths-opus-2/id1137172627 (this page in markdown: same URL + `.md`)
- Developer: [Felt Tip Inc.](https://appshunter.io/developer/306118159)
- Category: Music, Music, Education
- Price: $4.99
- Rating: 5.00/5 from 2 App Store ratings
- Age rating: 4+
- Requires: iOS 11.0 · 16 MB
- Languages: English
- Released: 2016-09-08
- Data updated: 2026-06-10
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/circle-of-fifths-opus-2/id1137172627/reviews.md

## What is Circle of Fifths, Opus 2?

Circle of Fifths, Opus 2 is a music theory tool for musicians exploring jazz and a variety of music styles that incorporate musical modes.

For a beginner version of Circle of Fifths, check out our Circle of Fifths, Opus 1 edition, where you can explore major keys and relative minor keys.

FEATURES
• Interactive circle: rotate the circle or tap on any key.
• Switch between the scale or circle chord progression.
• Play scale or chord progression out loud.
• Tap on individual chords to explore chord patterns.
• Includes both chord name and roman numeral notation.
• Choose from treble, bass, or alto clef.

Circle of Fifths was created by Lucius Kwok and Agnes Chan. Made in NYC.

## Key features

- Interactive circle of fifths
- Switch between scale and chord progression
- Play scales and chord progressions aloud
- Explore individual chord patterns
- Chord name and roman numeral notation
- Treble, bass, or alto clef options


## Frequently asked questions about Circle of Fifths, Opus 2

### What is Circle of Fifths, Opus 2?

Circle of Fifths, Opus 2 is a music theory application designed for musicians to explore advanced concepts like musical modes and jazz improvisation. It features an interactive circle to visualize key and chord relationships.

### What are the key features of Circle of Fifths, Opus 2?

Key features include an interactive circle that can be rotated, the ability to switch between scale and chord progressions, playing these progressions aloud, exploring individual chord patterns, and displaying chord names with roman numeral notation. It also supports treble, bass, and alto clefs.

### What is the price of Circle of Fifths, Opus 2?

Circle of Fifths, Opus 2 is available for a one-time purchase of $4.99. There are no in-app purchases or advertisements associated with this application.

### What devices is Circle of Fifths, Opus 2 compatible with?

Circle of Fifths, Opus 2 is compatible with iPhone, iPad, and iPod devices. It requires iOS 10.0 or later.

### How often is Circle of Fifths, Opus 2 updated?

The latest version of Circle of Fifths, Opus 2 was released on December 9, 2019. While the app was last updated in late 2019, it remains a stable tool for music theory exploration.

### What is the age rating for Circle of Fifths, Opus 2?

Circle of Fifths, Opus 2 has an age rating of 4+. This indicates it is suitable for users of all ages, with no mature content.

### Does Circle of Fifths, Opus 2 have ads?

No, Circle of Fifths, Opus 2 does not contain any advertisements. It is a paid application that offers an ad-free experience.

### How does Circle of Fifths, Opus 2 compare to Opus 1?

Circle of Fifths, Opus 2 is an advanced version focused on modes and jazz. Its predecessor, Circle of Fifths, Opus 1, is a beginner-friendly edition that explores major keys and relative minor keys.

## Version history (last 5 releases)

### 2019.12.5 — 2019-12-09

Moved the support FAQ to felttip.com/support/5ths-faq.html.

### 1.0.4 — 2019-09-20

Now supports Dark Mode.

### 1.0.3 — 2018-03-14

Minor updates to the layout.

### 1.0.2 — 2017-06-28

• Updated the More Apps button.
• Bug fixes.

### 1.0.1 — 2016-09-18

Added a link to the Musician’s Bundle, which includes our tuner app Tuna Pitch and Circle of Fifths, Opus 1.

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## More apps by Felt Tip Inc.

- [Tuna Pitch - chromatic tuner](https://appshunter.io/ios/app/tuna-pitch-chromatic-tuner/id313492710)
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- [Run 10k - couch to 10k program](https://appshunter.io/ios/app/run-10k-couch-to-10k-program/id350529744)
- [The Grix by eBoy](https://appshunter.io/ios/app/the-grix-by-eboy/id501431754)
- [RunQuest 21k](https://appshunter.io/ios/app/runquest-21k/id587108779)
- [Circle of Fifths, Opus 1](https://appshunter.io/ios/app/circle-of-fifths-opus-1/id637783279)

All apps by Felt Tip Inc.: https://appshunter.io/developer/306118159

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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 2026-06-10.*