Nearly every site in the Warrior Network publishes progressions: the hub and its instrument satellites voice them, the theory site discusses them, and the genre sites play their own. None of them answers the question a player asks with a chart in hand — given these chords, what key am I in, and what is each one doing? Progression Warrior exists to answer exactly that, from the symbols alone.
The reading
A line is scored against all twelve tonics in all seven modes by the network’s shared key detector: a chord that fits a key’s scale earns a point, a chord that does not costs one, and a line that opens or closes on the key’s tonic earns a point for each. When two readings score the same, the page says so and names both. Every chord is then written as a Roman numeral in the chosen key, and checked against a short list of declared moves — each one a rule over the chord and its neighbours, each one taken from a published source. The reader does all of this in your browser.
What it does not do
It does not tell you why a move sounds the way it does; that is a theory lesson, and the network’s theory site gives it. It does not play anything, draw any instrument, or mint a page for each famous progression — the network publishes those already. And it never writes a progression as a run of digits: the analysis here is in Roman numerals throughout.
How it is checked
Everything the site states is derived: the key, the numerals, the moves and every count on every page. Continuous integration re-derives all of it from raw pitch arithmetic, independently of the code that renders the pages, and fails the build if the two ever disagree.