Emily Sanders
Music Theory Educator & Harmony Researcher | Founder, ChordProgressionMaker.com
Every musician who has sat at a piano or picked up a guitar has eventually asked the same question: why do certain chords sound right together, and how do you find them? The answer is not mysterious — it is functional harmony, a system with clear rules, documented relationships, and predictable emotional effects that has governed Western tonal music for four centuries. The problem is not that the system is obscure. The problem is that most tools for working with chord progressions either require advanced theory knowledge to use or produce results without explaining why they work.
My name is Emily Sanders. I have spent years researching and teaching functional harmony, from the basics of tonic-subdominant-dominant function to the more complex terrain of secondary dominants, modal interchange, and jazz reharmonisation. ChordProgressionMaker.com was built out of a simple conviction: that the rules of harmony are learnable, that a tool built on those rules should explain them, and that a musician who understands why a progression works is better equipped than one who just knows that it does.
The tool on this site takes a root note, a key, and a progression style as input and applies documented diatonic chord lookup — the chords built on each scale degree, their Roman numeral function, and their relationship within the key — to generate chord sequences with functional logic behind them. The calculation is entirely client-side, runs in your browser with no server request, and produces results that are rooted in published harmony theory. To see exactly how the generation algorithm works, visit the How It Works page.
What I Research and Write About
Functional Harmony and Chord Function Functional harmony describes the role each chord plays within a key: tonic chords (I, III, VI) provide stability and rest; subdominant chords (II, IV) create movement away from rest; dominant chords (V, VII) create tension that resolves back to the tonic. I research and write about how these functions operate across different genres — from classical cadential patterns to blues and jazz — and how understanding function transforms the way a musician thinks about progression choice.
Diatonic Chord Theory and the Roman Numeral System The diatonic chords of a key — the triads and seventh chords built on each scale degree — are the vocabulary of tonal harmony. The Roman numeral system names these chords by their scale degree and quality (major, minor, diminished, augmented) in a way that transfers across keys. I research and write about how the diatonic system works, how chord quality is determined by scale structure, and how the same Roman numeral relationships produce different specific chords in every key. The FAQ covers the most common questions about how to use and understand chord progression results.
Chord Substitution and Harmonic Variation Beyond the basic diatonic system, tonal music uses chord substitution — replacing a diatonic chord with one that shares the same function but adds colour or movement — to create variety within a key. Secondary dominants (V/V, V/II), tritone substitutions, and modal interchange chords are the most common substitution types. I research how these substitutions work theoretically and write about how to apply them practically in songwriting and arrangement.
Voice Leading and Chord Voicing The way individual notes move between chords — voice leading — is as important as chord choice to the coherence of a progression. Smooth voice leading, common tones between chords, and the resolution of dissonance are principles that determine whether a progression sounds polished or awkward. I write about voice leading principles in accessible terms for musicians who have not studied counterpoint formally.
Why I Built This
When I was looking for a browser-based chord progression tool that generated progressions based on real harmony theory — not random chord combinations or machine-learning pattern matching — and that explained the function of each chord in the generated sequence, I consistently found tools that did one thing or the other but not both.
What I built is a tool that generates progressions from documented diatonic chord function, labels each chord with its Roman numeral and function, and provides enough explanatory context that a musician can understand why the suggested progression works — not just that it does. The goal is not to replace music theory knowledge. It is to make that knowledge accessible while the musician is working.
Accuracy Standards
Every chord formula, Roman numeral assignment, scale degree description, and harmony theory claim on ChordProgressionMaker.com is cross-referenced against established music theory literature. Chord generation follows documented diatonic harmony rules — not heuristic pattern matching. Where multiple valid chord names or enharmonic spellings apply to the same note set, this is explained. Limitations of the tool — including the fact that harmonic context and genre convention shape whether a progression “works” in practice — are stated explicitly. For details on how the tool handles data and why no audio or personal data is involved, see the Data Security page.
Tools on This Site
- Chord Progression Maker — chordprogressionmaker.com
Get in Touch
For content corrections, technical questions, or data requests, visit the Contact page or email directly: contact@chordprogressionmaker.com
Response times: technical and content questions within 48–72 hours. Privacy and data requests within 7 business days. GDPR requests within 30 days. CCPA requests within 45 days.
Emily Sanders is the founder and sole author of ChordProgressionMaker.com. For a full account of how content is researched and written, see the Editorial Guidelines. Last updated: June 2026.