The default I–V–IV–V challenge
The first challenge uses four bars at 80 BPM. Each bar asks for one chord degree: I, V, IV, then V. One finger represents I, five fingers represents V, and four fingers represents IV. The progression stays harmonically stable while you practice reading ahead, forming a clear pose, and holding it until the next target.
A four-beat count-in establishes tempo before scoring begins. During the sixteen scored beats, an incorrect gesture lowers the result but does not stop the sound or end the run.
How Match, Timing, and Stability work
| Score | Weight | What it measures |
|---|---|---|
| Match | 45% | Whether the chord playing on each scored beat matches the target. |
| Timing | 35% | Whether a correct new gesture became stable near the requested musical boundary. |
| Stability | 20% | Whether input avoided extra confirmed changes between scored beats. |
The total is a weighted combination, but the three components remain visible. Low Match means the pose or target was wrong. Low Timing means the correct pose arrived too early or too late. Low Stability means the tracker confirmed extra changes between beats.
Why Beat Lock is always active in a challenge
Camera frames do not arrive on a musical grid. If every confirmed frame changed the synthesizer immediately, device speed and small hand corrections would affect the rhythm. Beat Lock places a stable pending gesture on the next beat boundary scheduled by Web Audio. The scoring system can then compare every run against the same sixteen-beat structure.
Beat Lock still has a short delay, so Target, Playing, and Next remain visible. Move slightly ahead of the beat, check that the chord is queued, then hear it land with the pulse. Free Play includes Instant mode for immediate response.
Reading the result timeline
Each result cell shows target/played for one beat. A matching cell confirms that the requested degree was active. A missed cell shows both values, so an accidental II during a target IV is visible instead of hidden behind a percentage. The timeline contains musical events, not stored images of a hand.
The WebM download records the composited stage and generated audio when the browser supports local canvas capture. The MIDI download writes the played chord notes at 80 BPM. Open the MIDI in a DAW to change instruments or keep arranging.
How to improve the next run
- Watch Next, not only Playing. Confirm the requested gesture before the bar changes.
- Keep the wrist and fingertips inside the camera frame. Moving the whole hand changes intensity without changing the finger count.
- If Stability is low, make the folded fingers more distinct and hold the pose instead of correcting it repeatedly.
- If Timing is low but Match is high, begin forming the next pose one beat earlier.
- Use Mouse Mode to learn the progression before adding camera recognition.
Why variations stay in one tool
A different progression changes the notes, not the controls or scoring. Gesture Synth keeps those variations in one tool. This page explains the challenge and its score.