Several times a second, Chartless takes a small slice of the audio, figures out which musical notes are ringing, and asks: "which chord fits these notes best?" That's a guess. Guesses are noisy — a singer's melody note, a cymbal crash, or the blurry moment between two chords can fool any single one. Everything else Chartless does exists to clean that up.
Instead of judging each guess alone, the default engine treats the song like a road trip and keeps asking: "what's the most believable path of chords through everything I've heard so far?"
Staying on the current chord is easy. Switching to a new one costs something. So one weird moment of audio isn't enough to make the path swerve — blips get absorbed. But when evidence for a new chord keeps piling up, the path bends, and the display changes. Chartless also reads its answer about a second behind the newest audio, which is like grading the guesses with a little hindsight — by the time a chord shows, the music has already confirmed it.
If you turn the Sequence decoder off in Advanced Tuning, Chartless switches to jury duty. The last several guesses are the jurors — the Vote window dial sets how many. By default a challenger chord needs a clear majority of the jury before the display changes, and the Minimum hold cooldown stops flickering no matter what the jury says.
The interesting part is that not every chord pays the same price. A change that lands right on the beat is believed quickly; one that shows up at a musically unlikely moment has to work much harder. A handful of other common-sense rules — the kind a seasoned player applies without thinking — tune the vote further. The exact recipe is our secret sauce, but the spirit is simple: believe what a musician would believe, and never let one noisy guess flip the chart on its own.
Chartless finds the song's tempo — you'll see the bpm and a dot that pulses in time. Here's why that matters: real chord changes land on beats, and most of all on beat 1 of a measure.
So a new chord that arrives right on the downbeat is believed almost instantly. One on any other beat gets a small benefit of the doubt. And a "change" that shows up between beats has to work much harder to be believed — because it's almost always noise.
Most worship, folk, and campfire songs use just seven chords — the family that belongs to the song's key. Simple mode locks detection to those seven and turns everything else away at the door. Wrong-key guesses never even get a vote. It also expects changes at a relaxed, singable pace. If a song stays in one key, Simple mode is almost always the steadier chart.
Every preset is a saved combination of the dials. Simple is the worship & folk recipe (it turns Simple mode on too). Steady, Balanced, and Snappy trade calmness against reaction speed. Magic and Chris' Fav use the lookahead trick. Mine is whatever you've saved.