mcp_opendaw_reharmonize_progression
Reharmonize chord progressions by substituting chords with functionally equivalent alternatives using techniques like tritone substitution, secondary dominants, and modal interchange.
Instructions
Reharmonize a chord progression — substitute chords with functionally equivalent alternatives for richer harmony.
Reharmonization is the art of replacing chords while preserving (or enhancing) the harmonic function. This tool applies classical and jazz substitution techniques to transform a progression without changing its fundamental direction.
progression: Hyphen-separated chords (same format as create_chord_pads). "Am-F-C-G" = i-VI-III-VII in A minor. "C-Am-F-G" = I-vi-IV-V in C major.
technique: Substitution technique:
"tritone_sub" — Replace V7 with ♭II7 (Db7 for G7). Guide tones (3rd+7th) are shared, creates chromatic bass motion. Jazz standard.
"secondary_dominant" — Insert V7 of the target chord before it. e.g. before Am → insert E7 (V7 of Am). Adds forward motion.
"diatonic_sub" — Replace with functionally equivalent diatonic chord. I→iii or I→vi (submediant), IV→ii (supertonic). Shares tones.
"modal_interchange" — Borrow chords from parallel key (minor↔major). In major: ♭VI, ♭III, ♭VII from natural minor. In minor: IV, II from major. Adds color and emotional depth.
"passing_dim" — Insert diminished passing chord for chromatic bass motion between chords a whole step apart. Creates smooth bass lines.
intensity: How many chords to substitute:
"light" — substitute 1 chord (the most impactful)
"medium" — substitute ~30% of eligible chords
"heavy" — substitute all eligible chords
target_chord: Index of specific chord to substitute (0-based). -1 = auto select. Only used for tritone_sub and diatonic_sub.
Returns the reharmonized progression string + per-chord mapping + explanation of each substitution.
Example:
Tritone substitution on a ii-V-I
reharmonize_progression("Dm7-G7-Cmaj7", technique="tritone_sub")
→ "Dm7-Db7-Cmaj7" (G7→Db7, guide tones shared)
Modal interchange on pop progression
reharmonize_progression("C-G-Am-F", technique="modal_interchange")
→ "C-G-Am-Fm" (F→Fm, borrowed from C minor)
Secondary dominants for jazz
reharmonize_progression("C-Am-Dm-G7", technique="secondary_dominant")
→ "C-E7-Am-A7-Dm-G7" (E7 before Am, A7 before Dm)
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| intensity | No | medium | |
| technique | No | tritone_sub | |
| progression | No | Am-F-C-G | |
| target_chord | No |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |