Fretkey

Chords in any key

A songwriting companion bridging piano and guitar. Pick a root and a scale, then explore diatonic chords, secondary dominants, and borrowed chords for your next progression.

Root note
Scale
Current key C Major

Diatonic chords

The seven chords built from the notes of C Major. Press a chord to view it on the selected instrument, and click the + button to add it to the Progression builder.

Secondary dominants

Dominant 7th chords that tonicise each diatonic target. Great for adding pull and momentum.

Borrowed chords

Modal interchange — chords borrowed from the parallel minor for colour and surprise.

Progression builder

Tap + on any chord card to add it (up to 4). Guitar mode: click a slot to open the fretboard and drag the highlighted window to choose your voicing.

—
Slot 1
empty
—
Slot 2
empty
—
Slot 3
empty
—
Slot 4
empty

Solo chart

Notes to target when soloing in C Major. Toggle between key and pentatonic notes.

E
A
D
G
B
E
E
A
D
G
B
E
1
F
C
F
2
B
E
A
3
G
C
F
D
G
4
B
5
A
D
G
C
E
A
6
F
7
B
E
A
D
B
8
C
F
G
C
9
B
E
10
D
G
C
F
A
D
11
12
E
A
D
G
B
E
13
F
C
F
14
B
E
A
Standard tuning · E A D G B E
Root (C)
Pentatonic
Key note

Melody maker

Single notes from C Major. Press ▸ to hear a note, or + to add it to the melody. Toggle between key and pentatonic notes.

C
D
E
F
G
A
B

Melody 0/8

1
2
3
4
5
6
7
8

Plays one note per beat at 120 BPM.

Built for songwriters. Try I – V – vi – IV or spice it up with a ♭VII.