Ninth Flat Thirteen Chord Generator

Keep the natural ninth and add flat thirteen

C9(flat13) adds A-flat to the dominant ninth stack C, E, G, B-flat and D. The ninth remains D natural. This six-tone reference retains the perfect fifth G and does not add a natural eleventh.

C9(flat13) does not lower the ninth; C7(flat9,flat13) is a different formula. The upper A-flat is spelled as degree thirteen, not G-sharp. Retaining G makes the output distinct from a sharp-five replacement.

• Degree 1 is 0 semitones above the root in this reference.
• Degree 3 is 4 semitones above the root in this reference.
• Degree 5 is 7 semitones above the root in this reference.
• Degree 7 is 10 semitones above the root in this reference.
• Degree 9 is 14 semitones above the root in this reference.
• Degree 13 is 20 semitones above the root in this reference.

A listening test for 9(♭13)

Compare C9(flat13) with C9: only A-flat disappears. Hear D and A-flat separately to identify the natural ninth and lowered thirteenth. Select F and confirm F, A, C, E-flat, G and D-flat.

The Compare dominant ninth button retains your chosen root and octave and plays the comparison in root position. Set the current chord to root position for a direct comparison. The note buttons let you isolate the chord member that makes this quality different.

Dominant Ninth chord generator →

Follow the selected bass through each voicing

This 6-tone reference offers 6 positions. Root position starts with degree 1; First inversion starts with degree 3; Second inversion starts with degree 5; Third inversion starts with degree 7; Fourth inversion starts with degree 9; Fifth inversion starts with degree 13. The bass suffix beneath the chord symbol identifies the actual lowest tone.

Root position preserves compound ninths, elevenths and thirteenths at their original height. The inversion selector first moves the extensions into one octave, sorts by sounding pitch and rotates from the selected degree. These close pitch-class study voicings are different from the complete extended root-position stack; they are not recommended jazz fingerings.

Use the natural-nine and flat-thirteen combination when you want to hear those two upper colors together. A smaller practical voicing may omit the fifth, but this complete reference states every member so the output can be checked and exported.

Learn chord inversions →

Check C, F and A before transposing further

Begin with C and confirm C · E · G · B♭ · D · A♭. Use the F and A example buttons to transpose the same interval collection. Follow the MIDI values if an enharmonic spelling looks unfamiliar: changing the root shifts every sounding note by the same interval.

Use Root octave 2 for a lower reference or octave 5 for a higher one. A root change keeps your selected voicing; the example buttons return to root position. Reset restores C, octave 3 and root position. Stop sound ends the currently active chord or arpeggio.

All chord formulas and music theory →

What playback and the WAV file contain

The displayed notes are synthesized locally using sine waves after your click. The tool does not create a progression, transcribe a song, provide guitar fingering or simulate an acoustic instrument. No camera, microphone, registration or file upload is needed.

Download WAV saves the currently displayed voicing as a 2.4-second mono PCM file at 44.1 kHz with a short fade. It does not export the comparison chord or an arpeggiated performance. If Web Audio is unavailable, the note display and WAV download remain usable.

Theoretical note names preserve each degree and may use double accidentals. Equal-tempered playback gives enharmonic notes the same frequency. This browser tool does not add new extended-chord gestures to the webcam instrument; that instrument has its own triad, inversion and seventh controls.

Play the separate gesture instrument → · Local processing and privacy →