Why the Next Chord Is “Mostly Decided”

When you write a chord progression, the next chord could in theory be anything — but in practice some chords are far more likely to follow than others. The Progression Generator holds this “likelihood of moving from one chord to another” as a weighted map, and walks it to build progressions. This article explains that mechanism — what tends to follow what. For the chord roles themselves (T, SD, D), see tonic, subdominant, dominant; here we focus on the connections.

First, watch it generate

1. Open the Progression Generator
2. Generate a few in C major, 4 chords, “Standard”
3. Notice moves that show up often (F→G, G→C) and ones that almost never do (G→F)
4. Switch to “Melancholic” and watch which chords become likely

It’s random, yet it sounds plausible every time, because each step is a weighted die, not a fair one.

Likelihood isn’t uniform

After any chord, some next chords are likely and others aren’t. Roughly:

• After the dominant (G), the tonic (C) is likely — the pull to resolve
• After the tonic (C), almost anything works — high freedom
• After the subdominant (F), the dominant (G) is likely — the F→G→C flow
• A “backward” move like G→F is unlikely — it postpones resolution, a special effect

The generator stores these likelihoods as numeric weights and picks heavier edges more often. That’s why the output differs every time yet never strays far from familiar motion.

The mood filter reweights the map

Filters like “Standard” and “Melancholic” reweight the same map.

• “Standard”: makes the royal-road edges (T→SD→D→T) heavier
• “Melancholic”: makes edges toward minor chords (VIm especially) heavier

Same key, same chord set — which edges are heavy decides the “weather” of the song.

Walking it yourself

You can walk this map by hand:

1. Start on C
2. Pick a likely next chord (F or Am if unsure)
3. From there, pick another likely next
4. When you reach G, return to C to close

The generator just automates this with weights. Once you see the mechanism, you can read any progression by asking “why did it land in this order?”

What to try next

Generate five on “Standard” and find the two-chord move they share (probably G→C or F→G). Then generate five on “Melancholic” and compare which edges increased. With the likelihood map in your head, building from the common progression patterns by hand stops being a guess.

→ Watch the transitions in the Progression Generator