Harmonic analysis
Read in C major, the key of the tune. Taken on its own, with nothing around it, this excerpt is just as easy to hear in G major — a few bars are often not enough to fix a tonic, and that ambiguity is a real property of the music rather than a gap in the analysis.
| Chord | Roman numeral | Function | What it is doing | Confidence |
|---|
| C6 | I | Tonic | C6 is the tonic of C. It is where the progression is at rest. | High |
| Fm7 | iv | Predominant | Fm7 is a minor iv in a major key, borrowed from the parallel minor. Its b6 pulls down into the third of the tonic — one of the most recognisable sounds in the repertoire. Also readable as ii/bIII. | Medium |
| Bb7 | bVII7 | Dominant | Bb7 is the backdoor dominant of C. It approaches C from a whole tone below rather than from the fifth above — the b7 and b3 of the parallel minor resolving inward. | High |
| C7 | I7 | Tonic | C7 is the tonic, but built as a dominant seventh — the sound that defines the blues. The tonic keeps a b7 and stays at home anyway. | High |
| Bb7 | subV7/vi | Dominant | Bb7 is a tritone substitute — subV7/vi. It carries the same tritone as E7, the real dominant of A, but resolves down a semitone instead of down a fifth. Also readable as bVII7 / bVII7. | High |
| A7 | V7/ii | Dominant | A7 is functioning as V7/ii: a secondary dominant. It is the dominant of D, not of the home key, so it borrows the pull of a V-I and points it at ii instead. | High |
| D7 | V7/V | Dominant | D7 is functioning as V7/V: a secondary dominant. It is the dominant of G, not of the home key, so it borrows the pull of a V-I and points it at V instead. | High |
| G7 | V7 | Dominant | G7 is the dominant of C. Its third and seventh form a tritone, and that tritone is what makes the tonic feel due. | High |
What the analyzer found in it
iv - bVII7 - IFm7 - Bb7 - C7
A backdoor cadence in C: iv and bVII7 borrowed from the parallel minor, arriving at the tonic from below.
half cadenceG7
The progression stops on the dominant of C — a half cadence. It is unfinished on purpose.
High, medium and low next to each numeral are judgements about musical context, not probabilities. A low rating marks a bar that can honestly be read more than one way. How the ratings are decided →
The complete analysis of Yardbird Suite — every chord of the whole form, with its Roman numeral and its ii–V–Is marked on the chart — is in JamShed with the Practice Pass, ready to print. Open it in JamShed →
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Project 03 · Harmony
Project 07 · Jazz guitar
Project 05 · Harmony
