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New Released in April 2026
Second Inversion: The 6/4 Chord and Its Four Jobs
A second inversion chord has its 5th as the lowest note: C major as G C E. Figured bass writes 6/4 because C is a 4th and E a 6th above the bass. It is the one inversion theory books treat with care, since a 4th over the bass sounds unsettled.
No account, no download. The demo has limited content. Advanced features are in ChordRunner Premium.
- MIDI keyboard
- Digital or acoustic piano
- Guitar
- Computer, phone or tablet
Why 6/4 is special
Root position and first inversion can sit almost anywhere. A 6/4 chord cannot: the 4th above the bass wants to slip down to a 3rd. So in classical style a second inversion triad appears only in a few set patterns, and each pattern has a name.
The four six-four chords
- Cadential 6/4: I6/4 before V at a cadence (G C E, then G B D). The bass stays on G while the upper notes fall.
- Passing 6/4: the bass walks through, like C, D, E under I, V6/4, I6.
- Pedal (neighbour) 6/4: the bass holds still, like C E G, C F A, C E G (I, IV6/4, I).
- Arpeggiated 6/4: the bass moves through the notes of one chord, so the 5th lands at the bottom for a moment.
Second Inversion: The 6/4 Chord and Its Four Jobs
ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps.
Play the demoIn pop and on the keys
Pop writing calls it C/G and uses it freely: a G in the bass under C is a common way to move from C toward G. On the keyboard, second inversion has the gap at the bottom: G, then a jump to C, then E close by.
Practise all three positions
Play C in root position, first inversion and second inversion, then the same with F and G. ChordRunner accepts every position as the right chord, and its practice keyboard shows root, first and second inversion for any chord, so the 6/4 shape becomes as easy to find as the others.
The levels in ChordRunner
- Beginner: major, minor, augmented and diminished chords.
- Intermediate: adds sus2 and sus4.
- Advanced: adds 6th, 7th and 9th chords.
- Pro: adds 11th, 13th and altered chords; an adaptive mode adds the next family when you are ready.
Common questions
What does 6/4 mean in music theory?
Second inversion: a 6th and a 4th above the bass, so the chord’s 5th is the lowest note. I6/4 in C is G C E.
What is a cadential 6/4?
A tonic chord in second inversion placed right before V at a cadence. Many analysts read it as V with two notes leaning down onto it, so it is sometimes written V6/4 to 5/3.
Why does a second inversion sound unstable?
Because of the 4th above the bass. In tonal music a 4th over the bass wants to resolve down to a 3rd, so the chord feels like it still has to move.
Which instruments work?
A USB MIDI keyboard, detected automatically, or a piano or guitar through the microphone. Everything runs in Chrome or Edge on a computer, tablet or phone.
How is this different from apps where you tap the screen?
Tapping trains your eyes and fingers on glass. Here you press real keys or fret real strings, and the game hears the actual notes, so what you practise is exactly what you will play on your instrument.
Is everything in the demo?
The demo has limited content. Advanced features are in ChordRunner Premium.
Your instrument is the controller.
ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps. MIDI keyboard or microphone, both work.
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