Harmonizer for iPad

Finger playing Harmonizer note C

Harmonizer is an iPad application for exploring relationships between musical pitches.

Harmonizer is free, available via iTunes.

There isn't a lot of support for Harmonizer, but this page explains the basics.

Harmonizer FAQ

Q: How does the Harmonizer work?
A: See How the Harmonizer Works, below.

Q: Sometimes, when I'm playing something complicated, the Harmonizer stops playing. What's wrong?
A: Most likely, you are inadvertently triggering one of the iPad's "Multitasking Gestures." You can see how these work here. If this is a big problem, the feature can be disabled globally (in Settings:General:Multitasking Gestures). We are looking into ways to have the feature interact more predictably with Harmonizer; if we figure something out, there will be another release.

Q: What has changed in the latest version of the Harmonizer?
A: See Version History, below.

How the Harmonizer Works

1. Arrangement of Pitches

The pitches on the Harmonizer are arranged in a hexagonal matrix according to three interval types.

Pitches a perfect fifth apart are hexagons adjacent on vertical columns:

Harmonizer playing notes D G C F

Pitches a major third apart are hexagons adjacent on rising diagonal rows:

Harmonizer playing C, E and G

Pitches a minor third apart are hexagons adjacent on falling diagonal rows:

Harmonizer playing F, D and B

The pitches of major and minor triads are arranged in a triangle:

Harmonizer playing G sharp, C and E

The small triangle at the center of a triad will play the same triad as its adjacent hexagons:

Harmonizer playing C major triad via triangle key

2. Pitch Detection

When no tones are being played, the Harmonizer switches to "pitch detect mode."

In this mode, the Harmonizer analyzes the sounds coming into it and tries to identify the predominant pitch.

The identified pitch (or pitches, in the case of ambiguity) is highlighted on the display.

It will respond to singing or single notes played on musical instruments.

3. Shepard Tones

The tones produced by the Harmonizer are a special kind of sound known as Shepard Tones.

Shepard Tones are unlike tones produced by most musical instruments in that they have a "pitch class" (e.g. C, D, E), but not an octave (e.g. Middle C).

Because of this, on the Harmonizer, all the pitches of a given pitch class sound the same.

You can read more about Shepard Tones here.

4. Uses for the Harmonizer

Pitch Trainer for Infants

It is possible that children given an early introduction to the identities of musical pitches are more likely to develop absolute pitch (aka "perfect pitch"; see the Wikipedia article).

The Harmonizer was designed to make it easy to give young children exposure to pitch identities

The colors serve to identify pitches before the acquisition of language.

The touch interface is large enough that it can be controlled by children with rudimentary motor skills.

Chord Relationship Tutor

Due to the orthogonal arrangement of pitches on the Harmonizer, chord progressions all have the same "shape" — regardless of transposition.

5. Invertible Display

When the iPad is inverted, the Harmonizer display will switch to upside-down portrait mode.

If you are playing notes, these will also be "inverted" --- that is, reflected relative to C.

When inverted, major triads become minor and vice-versa (diminished and augmented triads remain the same).

Tactile Overlay Grid

Harmonizer with vinly hexagonal grid overlay

If you want to play the Harmonizer by feel, you can make a tactile overlay grid for it.

Download this template, print it out (card stock works best), staple it face-up under a sheet of clear vinyl (you can get this at Tap Plastics), and cut it out with a box cutter or x-acto knife (here's the recommended order of cuts).

I designed this so that a blind relative of mine could use it, but I find that it helps me play more accurately, too.

Version History

2010oct08 Version 1.1 Initial Release

2011jan23 Version 1.2 Fix to allow it to run under iOS 4.2.x