Same notes, different order. Pick the one whose bass note leads best from the chord before it — which is what the next panel does for you.
Every chord is chosen from its own inversions to sit as close as possible to the one before it. Nothing about which chords they are changes — only which of the same notes you put where.
Worked out by trying every note in turn as the root and matching what is left against the interval patterns. If the lowest note is not the root, it says so with a slash — C/E is a C chord with an E underneath.
A major triad is 0, 4, 7 semitones from its root. Every chord here is such a list added to a note number; the work is the order, the hands, the fingers.
Black keys are not centred. One rule, that the visible front of every white key is the same width, places all five, and C♯ sits nearer C, D♯ nearer E.
Press four keys and ask what it is: try each note as the root, measure the rest, match a pattern. The bass breaks ties, and a bass that is not the root gives a slash chord.
For each chord, try every inversion in every reachable octave and keep the one nearest the last. Most notes should not move.
Not the chord’s name or function, but the bass is most of what a listener hears as movement. C major with an E at the bottom is still C major; it feels like it is on its way somewhere rather than sitting still.
Three or four notes stacked in the bottom octave turn to mud: the lower the notes, the more the overtones of one interfere with the fundamental of another. Root and fifth, or just the root, leaves the harmony to the right hand where it stays legible. The tool follows that convention and lets you override it.
A chord with a specified bass that is not its root, written C/E and said “C over E”. Most of the time it is simply an inversion given a name; occasionally the bass note is not in the chord at all, which is a different and more interesting thing.
The right fingering depends on what comes next, and this page does not know. The numbers are the conventional ones for each shape on its own (thumb on the lowest note in the right hand, little finger on the lowest in the left); inside a real passage, a fingering that sets up the next chord beats one that is comfortable in isolation.
The theory is identical and the shapes are not, because a guitar cannot play any six notes you like. Guitar Chords works the same problem out against six strings and a hand that can reach four frets.
Not its name and not its function, but it changes what the bass is doing, and the bass is most of what a listener hears as movement. C major with an E at the bottom is still C major; it just feels like it is on its way somewhere rather than sitting still. That is why the choice matters even though the notes are identical.
Because the right fingering depends on what comes next, and this page does not know. The numbers shown are the conventional ones for each shape played on its own — thumb on the lowest note in the right hand, little finger on the lowest in the left — and they are a sound default. Inside a real passage, a fingering that sets up the following chord beats a fingering that is comfortable in isolation.
Because that is usually what sounds best. Three or four notes stacked in the bottom octave turn to mud: the lower the notes, the more the overtones of one interfere with the fundamental of another. Root and fifth, or just the root, leaves the harmony to the right hand where it stays legible. The tool follows that convention and lets you override it.
A chord with a specified bass note that is not its root — written C/E and said "C over E". Most of the time it is simply an inversion given a name, because the bass player or the left hand needs telling which note to take. Occasionally the bass note is not in the chord at all, which is a different and more interesting thing.
The theory is identical and the shapes are not, because a guitar cannot play any six notes you like. Guitar chords works the same problem out against six strings and a hand that can reach four frets.
Twelve-tone equal temperament and a standard 88-key layout. The keyboard proportions come from the equal-front construction described above with a black key about 0.58 of a white key's width, which is close to most modern pianos but not identical to any particular maker. Fingerings are conventional defaults for isolated chords. The voice-leading search minimises total semitone movement, which is one reasonable definition of smooth and not the only one — real voice leading also avoids parallel fifths and keeps the melody on top, and neither of those is modelled here.
This page has changed in 120 archived releases, but each of those was a site-wide pass, so none is attributable to this tool on its own and none is listed here. That is not a claim that the tool never changed — a release that reworked many pages at once may well have altered this one too. The changelog has them.