Chord Explorer — Analyze Piano Chord Relationships

The Chord Explorer in The Ultimate Piano compares any two chords and shows how they are related. It names what the second chord is in the key of the first, lists the keys both belong to, and shows the notes they share. One of the app's strengths is that you can play the pair back, so what the analysis claims is confirmed by your own ear.

It shows the raw material of good voice leading — the notes that can stay where they are when one chord moves to the next — and helps you understand chord progressions. You compare 2 chords at a time, building each from 12 root notes and 6 chord qualities.

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How to Use the Chord Explorer

Open the Chord Explorer from the feature menu (Learn → Chord Explorer), or use the keyboard shortcut Ctrl+Shift+E. It opens with C → F already selected, so you see a complete analysis straight away. The window has two columns of root notes, ordered like the Circle of Fifths (C, G, D, A, E, B, F#, Db, Ab, Eb, Bb, F):

1. Left column – your first chord (Chord 1)
2. Right column – your second chord (Chord 2)

For each chord:
1. Click a root note
2. A small menu opens next to it with the chord types
3. Choose the chord quality — Major, m, 7, maj7, dim or aug

The analysis updates as soon as both chords are set. Clear Selection starts over; Esc, the × or a click outside the window closes it.

Chord Relationship Analysis

The panel on the right reads from top to bottom: the two chords as Chord 1 → Chord 2, then three sections.

Direct Relationship

The Chord Explorer treats your first chord as the home chord and names what the second chord is in that key — for example "F is the IV (Subdominant) of C" or "Am is the vi (Submediant) of Cmaj7". The function names run from Tonic through Supertonic, Mediant, Subdominant, Dominant and Submediant to Leading Tone or Subtonic. Seventh chords keep their number (G7 is the V7 of C), and a chord only counts as part of the key when all of its notes are in it — otherwise the panel says so, for example "Bb is not diatonic in C major". The first chord has to be major or minor to serve as a key.

Below that you see three figures:

• Interval – the distance between the two roots, for example Perfect 4th
• Circle of Fifths Distance – how many steps apart the two roots sit on the circle
• Relationship Strength – Very Strong on the same root, Strong one step apart, Moderate up to three steps, otherwise Weak

Common Keys

A list of every major and minor key that contains both chords, each with the Roman numeral of both chords in it — C and F, for example, belong to C major (I, IV), D minor (VII, III), F major (V, I) and A minor (III, VI). This is where you see the different roles the same pair can play.

Common Tones and Voice Leading

The Common Tone Analysis lists the notes of both chords and highlights the ones they share, with their number and a Proximity rating from Very Close to Distant. Shared notes are what make smooth voice leading possible: they can stay where they are while the other voices move.

Play Sequence plays the two chords one after the other, the second placed as close to the first as possible, so you hear how the change sounds. Find Passing Chords opens Passing Chords with both chords already filled in.

Use Cases

• Songwriting – Understand why certain chord progressions sound good
• Arranging – Find the shared notes that keep a change smooth
• Theory Study – See which keys a pair of chords belongs to and what role each plays
• Improvisation – Identify common tones for melodic ideas

Voice Leading Tips

• Close relationships – Chords that share 2+ notes usually sound good together
• V to I – The classic dominant to tonic resolution
• Circle of fifths – Chords one step apart on the circle share a note and rate as a strong relationship

Use Passing Chords to find transition chords between any two chords, or explore chord structures visually in Learning Mode. Turn your chords into a full chart with the Leadsheet Editor.

Frequently Asked Questions

What is the Chord Explorer and how does it work?

2 chords are all you need: the Chord Explorer lets you select any two chords and instantly see their harmonic relationship — what the second chord is in the key of the first (for example the IV, Subdominant), the keys both belong to, and the notes they share. It helps you understand why certain chord combinations sound smooth or create tension.

How does the chord relationship help with songwriting?

2 shared notes are the threshold: the Chord Explorer shows the common tones between two chords, and chords sharing 2+ notes transition smoothly, while chords with fewer shared notes create more dramatic movement. This reveals why some progressions feel natural while others create surprise, so you can choose chords intentionally.

What is voice leading on piano?

Voice leading describes how individual notes move from one chord to the next. Good voice leading minimizes large jumps — notes move by step (1-2 semitones) or stay as common tones. The Chord Explorer shows you the common tones of the two chords you select, and Play Sequence lets you hear the change.

Can the Chord Explorer help me learn jazz harmony?

Yes. Jazz harmony relies heavily on chord relationships, especially functional progressions like ii-V-I. Across 12 roots and 6 chord qualities, the Chord Explorer shows the functional relationship between any two chords and the keys they share, helping you understand dominant resolution and common-tone connections that are fundamental to jazz.

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