Interactive Chord Function Map

It’s an interactive app that graphs out harmonic function on a kind of transit-system-like grid. To create a chord progression, you simply click on stations in the map or use the keys on your computer keyboard to choose and move around. The app will play each chord for you out loud as you add them to your path.

A station is a chord function in a given key. Select your desired key and mode next. You can pick from any of the twelve major keys in the key terminal drop down menu. This is followed by the line system toggle which switches the selected key to either functional minor or major. Functional minor follows the conventions of harmonic minor scales. This mean there are a leading tone diminished chord and a major dominant chord, which give better resolutions.

How to Use the Harmony App

In the top panel there are controls to adjust the sound character. There is the option of triad or seventh chord. Seventh chords has an extra note of colour/tension (four notes), whereas triads are simpler three-note harmonies. Also select either compact or open voicings. Open voicings spread out the chord tones over a greater range while compact voicings keep them closer together.

The bass seat control controls what chord tone appears in the lowest register. For example, if you want to retain the root note in the bass then you will have a more traditional sound. Or you could choose to invert the chord with the third, fifth and even seventh of the chord in the bass. It’s this control that becomes useful when you’re exploring particular harmonic sounds or voice leading. When using triads, if you choose seventh for your bass then the tool automaticly changes to seventh chords.

The cabin volume slider adjusts the master gain. The train pace slider controls the speed at which you send your entire route. While a fast pace will give you a sense of motion, a slow one will allow you to hear each chord more clearly as they progress in time.

All of the chord stations are laid out by function in the main map area. Tonic Family chords is on the left, Predominant chords are in the middle column and Dominant chords occupy the right-hand column. Select a station by clicking it and that chord will be included in your harmonic sentence.

The right hand panel is where the route of your built chord sequence appears. Clicking on a chord’s token removes it from the route. You can also use cadence tickets to load predefined progressions. These buttons quickly fill out the route with some of the most popular patterns such as deceptive ending or perfect authentic cadences. It’s a fast method of hearing familiar functional moves in action. Once you’ve loaded one of these routes you can edit it to add and remove stations.

Playing the whole sequence is as simple as pressing the dispatch route-train button once you’ve created a route. A little animated indicator travels along the paths between the chords you’ve selected. You get diagnostic feedback on every chord change; did it follow the expected function, or was it a more creative departure?

You do not need a mouse because the map works with a keyboard. To change settings simply tab around the controls. If you are looking at the map, use arrow keys to travel from station to station. To include the currently selected station in the route, press the Space or Enter key. Jump right to each of the stations by pressing numbers 1, 7 on the keyboard. Press the A key to set the station you just selected as main one.

Common tasks have keyboard shortcuts: Pressing the U key will back up a step in your progress; pressing R will send off whatever route you’re working on. It doesn’t matter where your mouse pointer is when you press these keys, as long as it is not inside an input field. This lets you try out multiple harmonic pathways quickly.

You can begin by hearing just tonic to dominant to tonic to get a feel for the harmonic pull in action. From there, you might try adding a more complex sense of tension by using a predominant chord such as an IV or a ii and then resolving. To check how the tool hears what you’ve done, use the diagnostic panel. There’s also an applied dominant station which is essentially a temporary tonicisation of the dominant that pushes harder towards resolution.

A handy shortcut to all of those controls exists in the form of the help panel, which will remind you what each button does and where your keyboard commands lie. Turn that on when you want a reminder, or if you just like things less cluttered, you have the option to go full screen. This is great if you’re showing off the tool or if you just want more room to see the map and routes.

Movement and expectation are at the heart of harmonic function. This brings that into focus with a tangible element: the path from one chord to another. Apply it to explore typical progressions or to find unusual connections. It provides instant visual feedback on how chord function relates to both the qualities of the chords and their voice leading.

The trick is there are no wrongs here. Each of the chords you connect will have an outcome you can listen to and hear if it works for your song. Add a deceptive turn. Add a dominant chord. Jump from tonic to predominant and don’t resolve right away if it seems too predictable. It is meant for exploration.

Pick out a key that you know like C major. Create a brief passage and send it off. Switch the mode to functional minor and listen to the same set of functional chords. Observe that the dominant chord has changed its quality in the minor mode. Move around the voicings and positions for the bass; this will allow you to discover the effect texture has on the functional weight of every chord.

So, explore the map and take your time. Because it’s a widget, you can interact with it while trying things out as you go along. It even allows you to back up one stop or clear your route and start fresh if you like. The results will help you see how some progressions are good for reasons that show up in classical harmony analysis. There are also creative twists and turns that provide interesting bends on what we expect to hear.

For composers seeking inspiration or students of music theory, this map offers a tactile approach to exploring harmony. It’s instanty understandable. You can see how elements relate together, hear them playing back, and get instant feedback. You have control over the settings so they match where you’re focusing (tonality, rhythmic flow, voice leading). Simply hit a key and start creating your harmonic journey.