Introduction
Many musicians know the feeling: once the key is clear, the real decisions begin. Which chord should you use? What function should it serve? And how do you check that choice not only in theory, but by ear?
Without a convenient tool, this quickly becomes slow and awkward. You have to recall chords from memory, look up cadences separately, and treat modulation as something that makes sense on paper but feels abstract in practice.
The Harmony page solves this in a practical way. It lets you see the chords in a selected key, hear them, compare their harmonic functions, test cadences, and understand how a piece can move into another key.
In this article, we will look at how this page works, what kinds of tasks it is especially useful for, and how to use it in real musical practice.
What the Harmony page is
Harmony is an online tool for working with chords inside a selected key. It presents harmonic material not as dry theory, but as a usable structure: which chords are available, what function each chord serves, which cadences can be built from them, and how you can move from one key into another.
The value of the page is that it connects several layers at once. You do not just see the chords inside a key. You can relate them to function, context, and sound. That makes the page useful not as a reference for its own sake, but as a tool for choosing, testing, and applying harmonic ideas.
How this page came to be
The Harmony page appeared around the same time as the rhythm trainer. The original idea was simple and practical: I wanted one place where I could see the main chords of a key and hear them as well. Not scattered across different sources, but right in the browser and free to use.
Over time, more material started to grow around that idea. I spent a long time collecting different cadences because I wanted more than just a list of chords. I wanted a set of common harmonic movements that could be previewed quickly in any key. That matters both for learning and for writing music: a cadence gives you a sense of motion, not just a list of functions on paper.
At the same time, I was also collecting material on modulations. I wanted to understand not only which chords belong to a key, but also how music can leave that key. What kinds of transitions are possible? What holds them together? Why do some of them sound natural while others create a sharper effect? That is how the page gradually grew beyond chords and cadences and added a separate layer devoted to modulation.
In its early version, the page was called “harmony generator.” It showed the main chords of a key in a table: triads, sus chords, seventh chords, and chords with added 9ths, 11ths, and 13ths. Even then, it was already useful for musicians who wanted to orient themselves inside a harmonic field without building everything manually.
Later, the page became broader and more practical. Quite recently, I reworked the main chord table: I added 6th chords and power chords, and I also improved the sound. Now the chords are not previewed only with a synthesized guitar sound. You can layer several instruments at once and get more lively timbral combinations. As a result, both cadences and modulations feel more musical.
Work on the page is still ongoing. I continue to collect interesting cadences so the tool remains not a static catalog, but a living, practical library of harmonic movement.
What problems it solves
The Harmony page is especially useful when you need to make a musical decision, not just recall a term.
1. It helps you quickly see the chords inside a key
When you are choosing a key for a song, analyzing an existing progression, or looking for options for an arrangement, it helps to know what chord set is actually available to you. And not only basic triads, but also more practical working options: sus chords, seventh chords, extensions, 6th chords, and power chords.
That saves time. Instead of holding everything in your head or jumping between scattered charts, you see the available material in one place.
2. It helps you choose a chord by function
A chord function is the role a chord plays inside a key. In practice, that matters more than it may seem. One chord creates stability, another pushes the music forward, and a third creates tension and wants to resolve.
When the function is visible right away, the choice becomes more intentional. You are no longer picking chords blindly. First you decide what the music needs at that point: rest, preparation, tension, or a turn. Then you listen to the options and choose the one whose character fits best.
3. It gives you real context through cadences
Chords are useful on their own, but in music they almost always work in motion. That is why cadences are not an extra option here. They are one of the key parts of the page. They let you hear how a function unfolds inside a progression.
This is useful both for learning and for writing music. In the first case, you start hearing common harmonic patterns more quickly and recognizing them in songs. In the second, you get a starting point for your own progression, which you can then develop for a specific musical idea.
4. It helps make sense of modulation
Modulation is one of those topics that can easily turn into overloaded theory. But the practical question is usually simpler: how do you move from one key to another in a way that sounds convincing?
When different kinds of modulations are collected in one place, they are easier to understand as musical solutions rather than abstract schemes. That is useful both for analysis and for your own material when you want to expand the harmony and move beyond a single tonal center.
How to use Harmony in practice
To choose a chord by function
This is one of the most useful use cases. Suppose you need a dominant chord in the key of B minor. You open the page and immediately see which scale degrees carry dominant function. Then you can listen and decide which option feels right: more direct, softer, or more tense.
This workflow is useful because you move from musical role to specific chord, not the other way around. First you decide what the harmony needs to do. Then you choose the sound that fits that role.
For songwriting and chord progressions
When your usual progressions start to repeat themselves, the Harmony page helps you break out of the pattern without resorting to random trial and error. You can choose a key, review the main functions, listen to a few cadences, and use the one that best matches the mood of the section.
If you want to take the next step, you can move that material into the Song Builder: build the full progression, work with tempo and inversions, and hear it in a longer form.
For analyzing other people’s music
If you are analyzing a song, the page helps you quickly check which chords are diatonic, where a functional shift begins, and where a modulation might already be emerging. It does not replace full analysis, but it makes it much faster to orient yourself inside the material.
For learning and teaching
For self-taught musicians, the page gives you a framework: instead of trying to hold everything in your head, you can work through harmony via a specific key, function, and sound. For teachers, it is useful because it helps show students not only the name of a function, but how that function actually feels inside a progression.
Why this approach works especially well inside Six Strings App
The strength of the Harmony page is that it is not isolated from the rest of the site.
If you find the chord you need by function and sound, the next step is to open Chords, Arpeggios, Scales and choose a playable fingering. If you want to orient yourself more quickly in major and minor, the Circle of Fifths is right there. And if you want not only to understand function but also to recognize it by ear, the logical next step is the Chord Function Ear Trainer.
Because of that connection, theory does not stop at a table. It moves into ear training, the fretboard, and real musical action.
Where to start
The easiest way to use the page is this:
- Choose a key.
- Look at the main chords and their functions.
- Listen to the options on the scale degree you need.
- Open the cadences to hear that chord in motion.
- If you find the right option, go to Chords, Arpeggios, Scales for the fingering.
Even this simple route gives you practical value without requiring deep theoretical study.
FAQ
What does the Harmony page show?
It shows the chords of a selected key, their functions, cadences, and possible modulations, with audio playback.
What are chord functions for?
Functions help you understand the role of a chord inside a key: stability, motion, tension, and resolution.
Can I use Harmony for songwriting?
Yes. The page helps you choose chords by function and sound, listen to cadences, and find ideas for progressions.
Why are modulations useful on this page?
They help you hear and understand how a piece can move from one key to another in real music.
What should I do after choosing a chord?
Go to Chords, Arpeggios, Scales to find a comfortable fingering and explore related scales.
Related tools
- Harmony — the main page this article is about
- Chords, Arpeggios, Scales — the next step after choosing a chord by function
- Circle of Fifths — for quick navigation through keys
- Song Builder — for building and previewing a progression after choosing harmonic material
- Chord Function Ear Trainer — for developing an ear for harmonic function