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Measurement

What iQuantize actually measures

Updated 3 August 2026

Seven skills, one shared vocabulary

The list is not a scoring gimmick invented for an app — it is the vocabulary a teacher already reaches for. Note accuracy asks whether the notes you were given actually landed; a low score there means notes you know are missing, not a subtle nuance.

Timing splits into three separate numbers, covered in their own section below, because keeping them apart is the most useful thing this page can tell you.

• Dynamic control failing sounds close on tape and reads flat on the chart: the ghosts and accents land, in the wrong zone. The ghost-notes guide has the drill for it.
• Dynamic range failing is a groove that never gets quiet or loud — everything sits in a safe middle where nothing costs you anything.
• Limb independence failing is your feet arriving a beat late once the hands get busy, which is what that guide spends its time on.

Timing with the click, versus timing stability

Timing with the click measures distance from the grid: how close each hit sits to where the chart says it should land, while the click is audibly running.

Timing stability measures distance from yourself: how tightly your hits cluster around your own average, regardless of whether that average sits early, late, or dead on the beat.

Picture someone whose every hit lands 15 ms behind the click, and lands there every time. iQuantize tells them so — the per-bar map reads 8 notes late (+15 ms) — and then scores them 99 for timing with the click and 97 for stability. It names the offset without marking them down for it, because sitting a fraction behind the beat is a choice a lot of good drummers make on purpose.

What moves the numbers is not where your average sits. It is how far your hits scatter around it. The same player with a dead-centre average and 60 ms of scatter drops to 67 on stability, and the finding that comes back reads: The beat spacing is uneven. Bars 5–8 are close to the click, but the gaps between hits change.

So the two ask for different work. A consistent offset moves once you know it is there — listen a fraction earlier, or shift where your ear expects the beat to sit. Scatter is a control problem, and no single nudge fixes it; it takes slower, more deliberate reps until the hand does the same thing twice. Rushing vs dragging has the drill for each.

Two more it works out and never shows you

The app also calculates two things it keeps to itself. One is a reading number. It cannot tell whether you were sight-reading that chart cold or playing something you have known since you were fourteen, and those are not the same achievement, so the number would not mean what it appeared to mean.

The other is tempo readiness: whether this groove is clean enough for you to push the metronome up. That steers what comes up next instead of appearing as a skill, because “ready for 96 BPM” is a decision about your practice, not something you would recognise as a strength of your own.

When a skill is left blank

A skill iQuantize could not measure shows no number at all — never a zero. A zero says “you failed this”; a blank says “we do not have enough to judge”, and those are different things to put in front of someone practising alone.

• Internal pulse needs two complete bars with no click after a valid count-in, plus a recovery bar back on the beat. Anything short of that comes back as not measured, or low confidence.
• Dynamic range is only assessed when the chart itself authors real dynamic contrast. A groove written at one volume throughout gives the app nothing to measure a range against.
• Limb independence is only assessed when the chart actually asks the feet to do something independent of the hands. A hands-only chart does not get a free, meaningless 100.
• Dynamic control shows Dynamics are not scored yet when your kit is sending nearly the same volume for every hit. Set the velocity zones first: there is no way to grade soft against loud when the hardware is not sending the difference.
• Note accuracy below 55% stops the rest of the report. You cannot read the pocket, the dynamics or the limb balance of a groove that was not really played.

One take is a snapshot; the shape takes weeks

Seven numbers from one take describe one groove on one evening, which is not enough to plan a month around. Every completed take stores its results, and tapping a skill in Progress opens two charts for that skill alone: a daily average over the last 30 days, and a weekly average over the last 30 weeks. Timing stability on a Tuesday means very little. Timing stability across eleven weeks is the thing you are trying to move.

There is also a way to start from a measurement instead of a guess. The Skill Checkup is one 24-bar evaluation groove at 80 BPM — a money beat, a kick-reading passage, an open hi-hat move, some accents and ghost notes, and two short stretches with the click switched off. One take is enough; play up to three and it takes the middle. Out of it come the same seven skills and a Learning Plan: six to eight named grooves from the library, each with one line saying why it is on your list.

Why this vocabulary matters

A student who knows their weakest of the seven knows exactly what to put in front of the kit on Tuesday, instead of guessing at “tightness” in general. A teacher who can see the same seven numbers does not have to spend the first ten minutes of a lesson working out what happened last week — they can start from where the chart says the gap actually is.

There is no dashboard and nothing to send. The two of you look at the same screen on the student’s own device, which is the whole mechanism, and for a weekly lesson it is enough.

The seven skills

Note accuracy

Whether the notes the chart asked for actually landed, with extra hits counted against you.

Timing with the click

How close each hit sits to the grid while the click is running.

Internal pulse

Whether tempo holds through a section where the click drops out.

Timing stability

How tightly your hits cluster around your own average — independent of being early or late.

Dynamic control

Whether ghosts, normals and accents land in the zone the chart asked for.

Dynamic range

How much real contrast exists between your softest and loudest hits.

Limb independence

Whether your feet keep up with what your hands are doing.

Common questions