Toz - Geometric Music
Harmony has a shape.
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
iPad
You've heard harmony. Now see it.
On the Tonnetz grid, a major chord is a triangle pointing up. Flip it — minor chord. Add a corner — seventh chord. These aren't icons. They're the actual geometric structure of the notes.
Toz makes this 200-year-old music theory map something you can play.
--- ON THE GRID ---
Draw Chords
Drag to connect notes. △ = major, ▽ = minor, ∟ = dominant 7th. Hear the chord as you draw it.
Build Progressions
Link shapes into a sequence. A bar at the bottom tracks your harmonic path.
Set a Key
Tap any note as your tonal center. Pick major, minor, harmonic minor, or melodic minor. The grid shows what's in — and what's out.
MIDI Input
Plug in a keyboard. Every chord you play maps to a shape on the grid, in real time.
Chord Map
A reference for every triad, seventh chord, and scale shape on the Tonnetz. Tap to hear.
--- MADE FOR ---
- Composers who think about harmony spatially
- Music theorists doing Neo-Riemannian analysis
- Students who'd rather see intervals than just read about them
- Anyone who's wondered what their chords actually look like
--- HOW IT WORKS ---
The Tonnetz puts the circle of fifths, major-third cycles, and minor-third cycles on one grid. Chords stop being abstract symbols — they have positions, neighbors, and distances.
Move one note. The shape transforms. So does the sound.
Toz Pro
You may purchase an auto-renewing subscription through an In-App Purchase.
• Auto-renewable subscription
• 1 month ($1.99), 1 year ($14.99), and lifetime ($19.99 one-time purchase) options
• Your subscription will be charged to your Apple ID account at confirmation of purchase and will automatically renew unless auto-renew is turned off at least 24 hours before the end of the current period.
• Current subscription may not be cancelled during the active subscription period; however, you can manage your subscription and/or turn off auto-renewal by visiting your Apple ID Account Settings after purchase.
• Privacy Policy: https://tozapp.tech/privacy
• Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
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Bug fixes and improvements.
The developer, 令川 潘, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Usage Data
Data Linked to You
The following data may be collected and linked to your identity:
- Identifiers
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- 令川 潘
- Size
- 25.1 MB
- Category
- Music
- Compatibility
Requires iPadOS 16.2 or later.
- iPad
Requires iPadOS 16.2 or later. - Mac
Requires macOS 13.1 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPad
- Languages
English and 3 more
- English, Japanese, Korean, Simplified Chinese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Pro Yearly $14.99
- Pro Lifetime $19.99
- Pro Monthly $1.99
- Copyright
- © 2026 LingChuan Pan