About Drum Rudiment Coach

Drum Rudiment Coach covers 16 essential rudiments in 5 levels, from the single stroke roll to the ratamacue. Tap the left and right pads (F and J keys work too), or clap into the microphone, and every stroke is checked twice: did it land on the beat, and did the right hand play it? Each mistake gets one named hint right away.

How it works

• A take is one bar of count-in clicks, then the rudiment twice. Hits during the count-in are ignored.
• Hit detection runs in an AudioWorklet on the audio thread. It measures the loudness of each 64-sample slice (about 1.3 ms), keeps a slowly moving noise floor, and reports a hit when the loudness jumps well above both the floor and the previous slice. A short quiet period afterwards stops one hit's echo from counting twice. There is no AI model: just arithmetic on loudness.
• Taps are timed from the key or touch event, mapped onto the same audio clock as the clicks, and carry the hand that tapped them.
• Scoring: each hit is matched to the nearest written stroke that has not been claimed yet. Within the "on the beat" window it scores. A little outside, it is rushed or dragged. A hit on time but from the wrong hand is a wrong-hand mistake. Too far from every stroke, it landed between strokes. A written stroke with no hit by the time its window closes is missed; a missed grace note gets its own hint. 75% of strokes on the beat (with extra hits counted against you) passes.
• Windows scale with the rudiment: for quarter notes at a moderate tempo a hit within 60 ms of the beat counts as on the beat. For sixteenth notes the window tightens (never below 30 ms), because the strokes themselves are closer together.
• Mic mode grades timing only. A microphone cannot tell your left hand from your right, so mic takes skip the hand check. Use the pads when you want sticking checked.
• Flams and drags: a flam is a soft grace note 0.15 beats before a loud main note, played by the opposite hand. A drag is two soft grace notes (0.3 and 0.15 beats before) before the accent. The main note still lands exactly on the beat.

The hints

• "You rushed that stroke": your hit came early. Wait for the click to arrive, then strike with it.
• "You dragged behind the beat": your hit came late. Get ready earlier, and start the stroke as the click begins.
• "That hit landed between strokes": the hit was not near any written stroke. Count the pattern out loud and strike only on the written strokes.
• "Wrong hand": the stroke was on time but from the wrong hand. Check the sticking line: R is your right hand, L is your left.
• "Add the grace note before the accent": a flam or drag went by without its soft grace note(s). Play them just before the accent, from the opposite hand.
• "You missed a stroke": a written stroke went by with no hit. Keep counting through the silent beats.

Each hint shows the error in milliseconds. After the take, a summary names your most common mistake.

The levels

• Level 1, rolls and paradiddles: single stroke roll, double stroke roll, single paradiddle.
• Level 2, more paradiddles: double paradiddle, paradiddle-diddle, triple paradiddle.
• Level 3, stroke rolls: five, seven, nine and thirteen stroke rolls: doubles finished by one accent.
• Level 4, flams: flam, flam tap, flam paradiddle.
• Level 5, drags and ratamacues: drag (ruff), single drag tap, single ratamacue.

Passing any rudiment in a level unlocks the next. Quiz mode picks 5 rudiments from a separate set you have never practised, including left-lead versions, and scores each one.

These 16 are a teaching subset of the 40 International Drum Rudiments standardised by the Percussive Arts Society in 1984. The full list adds the single stroke four and seven, multiple bounce roll, triple stroke roll, six, ten, eleven, fifteen and seventeen stroke rolls, flam accent, flamacue, Swiss Army triplet, double drag tap, Lesson 25, drag paradiddles and more ratamacues.

Latency

Every device adds a little delay between the moment a click is scheduled and the moment you hear it, and between a hit and the moment the microphone delivers it. Bluetooth headphones can add 150 ms or more. If hits you feel are on time keep showing as late, use wired headphones or your device speakers, and keep the tempo slow until the hits land together.

Playing with speakers: the clicks play only during the count-in when using the mic, so the microphone does not hear the click as a hit. With headphones, switch on Click through the whole take in Settings.

Resources: learn from a real teacher

For real instruction, find a local drum teacher or a community music school. A teacher can watch your grip, rebound and posture in a way no app can.

Privacy

Your audio never leaves your device. In mic mode the signal is measured in your browser and discarded block by block; only hit times are kept for the current take. The microphone is only on while you are on a practice screen in mic mode, and turns off when you go back to the list, press "Turn off", switch to tap mode, or switch to another tab. See the Privacy page for the full details.

Disclaimer

This is a home practice tool, not a teacher, therapist or safety device. Everything runs on your device: no video, audio or images are sent anywhere. Feedback is automatic and can be wrong. For real instruction, learn from a qualified drum teacher, linked on the Resources page.

Accessibility

All controls are keyboard reachable; the pads respond to F (left) and J (right). Feedback is shown as text as well as colour, and the coach line is announced to screen readers. Celebrations respect reduced-motion settings where the browser reports them.

Credits

Built by Toolantern. No audio or video is collected, no model is downloaded, and no third-party code runs in this app: the hit detector and scorer are written for this app and ship with it.