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Metronome

Tempo · Time signature · Subdivision · Accents

120
♩ = BPM
Moderato

Tap a beat: accent · normal · muted

Tempo
Time signature
4
Subdivision
Sound
Volume

Programme note. The first beat — the one — glows in brass. Tap picks up your tempo, the subdivision lays eighths, triplets or sixteenths under the pulse, and every beat can be accented or muted with a fingertip. The space bar starts and stops.

II

Tuner

Chromatic · Instrument presets · Adjustable concert pitch

Instrument
—
— Hz
−50−250+25+50
— cents
Activate the microphone, then play a note.
Concert pitch A 440 Hz
Guitar · E A D G B e

Tap a string to play its reference tone for tuning by ear.

Note. A single plucked open string is enough — don't fret it. The matching string glows gold, and the needle shows the deviation in cents. Concert pitch A lets you tune to 440, 442 or historical pitches; microphone access requires HTTPS.


Programme Notes · № I

On the Metronome

A short companion to tempo, meter and the discipline of the steady pulse.

A brief history

The mechanical metronome as we know it was patented in 1815 by Johann Nepomuk Maelzel, building on earlier work by Dietrich Nikolaus Winkel. Within a few years Beethoven was writing M.M. markings — Mälzels Metronom — over the staves of his symphonies, and an entire vocabulary of measurable tempo entered the score. Today the same idea lives in a sliver of JavaScript: a precise clock, a click, and a steady visual pulse.

What BPM really means

BPM stands for beats per minute. A setting of 60 BPM means one beat every second; 120 BPM means two beats per second — the natural cadence of a brisk walk. The note value that receives the beat is set by the lower number of the time signature: in 4/4 the quarter note is the beat, in 6/8 the dotted quarter (or, for slow practice, the eighth). Setting the right reference note matters; a "6/8 at 80" can mean two very different things depending on whether you count eighths or dotted quarters.

Italian tempo vocabulary

Long before numerical BPM, composers used Italian words to describe the character and pace of a movement. These markings remain useful because they describe feel, not just speed:

Largo
broad, very slow40–60
Adagio
at ease, slow66–76
Andante
at a walking pace76–108
Moderato
moderately108–120
Allegro
lively, fast120–156
Vivace
vivacious156–176
Presto
very fast168–200

How to practise with a metronome

The most common mistake is to begin at performance tempo. Start instead at a speed where the passage is genuinely clean — every note in place, every rhythm honest. Once it sits comfortably, raise the tempo by four to six BPM and repeat. Two short, focused sessions of fifteen minutes a day produce more lasting accuracy than an hour of frustrated approximation.

A second technique: practise subdivisions. Set the click to half the working tempo and place two notes on each click, or use a 6/8 grouping to feel the inner triplet. Subdivision exposes uneven sixteenths and rushed triplets that a single click on each downbeat will hide.

"Without a sense of time, music does not exist. The metronome teaches the body to trust the silence between the beats." — a common piece of conservatoire wisdom

Reading the visual pulse

This metronome lights the first beat of each bar in gold. That downbeat is the harmonic and rhythmic anchor: in 3/4 it carries the waltz, in 4/4 it shapes the phrase. The remaining beats are softer pulses around it. The pendulum swings once per beat, mirroring the wooden Maelzel device. Use the visual when the click feels too clinical, and trust your ear when it does not.

Programme Notes · № II

On the Chromatic Tuner

Concert pitch, cents, equal temperament — and how this tuner actually listens.

The pitch we all agree on

Modern Western music is anchored to A4 = 440 Hz, the so-called concert pitch. It was formalised as an international standard in 1939 and codified by the ISO in 1955, replacing centuries of regional disagreement in which orchestral A could sit anywhere from roughly 415 Hz (Baroque) to above 450 Hz (late-romantic central Europe). Some ensembles still tune to 442 or 443 Hz for a brighter sound; many historical-performance groups stay at 415 or 392 Hz. This tuner uses the global standard of 440.

Cents — the small change of pitch

A cent is one hundredth of an equal-tempered semitone. There are twelve semitones in an octave, so the octave contains exactly 1200 cents. Three to five cents is the limit of what a trained ear can reliably detect on a sustained note; one cent is inaudible. When the needle on this tuner reads ±5 to ±10 cents you are, for practical musical purposes, in tune. Below five cents you are perfectly in tune. Above twenty cents the note is audibly sour and a casual listener will hear it.

Why all twelve notes do not "fit" perfectly

The piano, the fretted guitar and almost every modern instrument use equal temperament: the octave is divided into twelve mathematically equal steps. This is a compromise. Pure intervals derived from the harmonic series — a just major third, a Pythagorean fifth — are slightly different from their tempered counterparts. Equal temperament smears those small errors evenly across all keys so that every key sounds equally good (and equally imperfect). It is the reason a tuner reading 0 cents on every string still leaves a chord that is a few cents away from acoustic purity. This is normal and a feature of the system, not a defect of your instrument.

How this tuner hears you

When you grant microphone access, a short window of the incoming audio — roughly 4096 samples, about a tenth of a second — is analyzed with the McLeod pitch method, a close relative of the well-known YIN algorithm. The signal is compared with delayed copies of itself; the shortest delay at which it matches its earlier shape almost as well as at the best one gives the period (this keeps the reading from dropping an octave), and from the period the fundamental frequency follows. The result is smoothed with a short rolling median to suppress the wobble of pick attack and string decay, and the closest equal-tempered note is reported with its deviation in cents.

Practical tuning advice

Pluck a single open string firmly but without forcing it. Let the note settle for about half a second before reading — the pitch of a freshly plucked string always sharpens briefly under the attack, then drops as it stabilises. Tune up to the target, never down: if you have overshot, drop well below and approach from underneath. This keeps the wraps of the string taut around the tuning post and helps the instrument stay in tune longer.

For guitar in standard tuning the six open strings are E A D G B e — from the low sixth string (82.41 Hz) up to the high first (329.63 Hz). After every string is at zero cents, play a clean open chord and listen: if anything sounds beating or restless, your saddle intonation or your string age may be the cause, not the tuner.

"Tune slowly, listen twice, and never trust a string you have just changed." — a luthier's reminder
Reader's Questions

Frequently asked

Why does my browser ask for microphone access?

The tuner has to listen to your instrument. Browsers protect the microphone behind an explicit permission prompt, and the audio is processed locally on your device — nothing is uploaded, stored or transmitted.

Does the tuner work for instruments other than guitar?

Yes. The chromatic engine recognizes any pitched sound from roughly 40 Hz to 1500 Hz, which covers bass guitar, ukulele, violin, mandolin, woodwinds and the human voice. The six-string reference panel below the needle is only a convenience for guitarists.

Why do I sometimes see a flickering note name?

Pick attacks, room noise and lower-quality microphones can briefly confuse pitch detection. Pluck softly and consistently, and wait until the note stops decaying. A short rolling-median filter inside the tuner already removes most of the flicker.

Can I use the metronome offline?

Once the page is loaded, both tools run entirely client-side. You can switch off your network and the metronome and tuner will continue to work. For a true offline experience, our Android app includes the same engines plus the circle of fifths and chord builder.

What time signatures does the metronome support?

The default presets are 2/4, 3/4, 4/4 and 6/8 — the meters most commonly encountered in pop, rock, folk and most classical repertoire. The first beat of every bar is accented automatically.

Why does keyboard "Space" start and stop the click?

For practice on an instrument, a hand-free shortcut is essential. Tapping the spacebar starts or stops the metronome instantly so you can keep your hands on the keyboard, fingerboard or bow.

Practising with the metronome and the tuner

What the tools do is explained above. This is how to work with them — and which mistakes happen most often.

Metronome

In practice: the tempo ladder

A metronome does little good if you simply let it run alongside you. The method that reliably works is the tempo ladder: 60, 66, 72, 80, 88, 96, 104. Start at the tempo where the passage succeeds three times in a row without error — not the one where it “nearly” succeeds. After three clean run-throughs, move up one step. At the first mistake, drop two steps.

Dropping two steps rather than one is where almost everybody wants to cut the corner, and it is the actual mechanism. A mistake at 96 does not originate at 96; it is already present at 88, where it can still be corrected. Drop only one step and you keep practising at the very tempo that produced the error.

Second: never take a whole piece, take the difficult four bars plus one bar either side. Those six bars are the unit of practice. A piece does not get faster by being played end to end often enough, but by its three bottlenecks ceasing to be bottlenecks.

Write down the tempo you reached, with the date. It sounds bureaucratic, but it is the only way to see progress that happens in increments of five over weeks. Without a note you remember the feeling, and the feeling is unreliable.

Taking the click away — the real exercise

Once a passage sits at the target tempo, thin the metronome out rather than switching it off. First stage: in common time set the beat count so it clicks only on one and three. You now carry the pulse between the clicks yourself. Second stage: only on beat one. Third: only on the first beat of every second bar.

This shows incorruptibly whether the tempo is genuinely steady. Arrive at a click two bars away without a jolt and you have internalised the pulse. Arrive consistently early and you are playing faster than you think — by far the most common direction of drift.

A more demanding variant from jazz practice: have the metronome click only on two and four. The click is then no longer the downbeat but the backbeat, and the sense of beat one has to come entirely from you. Two weeks of this and you hear rhythm differently.

In compound metres it pays to set the reference value deliberately. “6/8 at 80” is ambiguous: quavers or dotted crotchets? For learning, set quavers and get six clicks per bar; for playing, set dotted crotchets and get two — and only then does the bar sound like six-eight rather than like six counted quavers.

Common mistakes

The click becomes a crutch. If you can only play a piece with the metronome and wobble immediately without it, you have not practised the pulse but the act of reacting to a signal. Thinning it out, as above, is not an extra but part of the exercise.

The target tempo as the starting tempo. There is a number at the top of the piece and many people begin there. It is the goal after two weeks. A passage played almost-correctly thirty times is harder to fix than one never played wrongly.

Speeding up in a crescendo. Loudness and tempo couple almost automatically in the body: louder becomes faster, quieter becomes slower. The metronome makes this mercilessly audible, which is exactly why loud passages should be practised with the click on.

Playing on after a mistake. The reflex to play through a slip belongs on stage, not in the practice room. In the practice room: stop, isolate the spot, drop the tempo, three clean repetitions, continue.

Working too long in one go. Metronome work is concentration-intensive. After roughly twenty minutes accuracy measurably drops and you begin consolidating errors rather than removing them. Two blocks of twenty minutes beat one of fifty.

Tuner

In practice: a tuning routine that holds

The direction matters more than most people assume. Always approach the target pitch from below, never from above. If you are sharp, wind clearly below the target — about a quarter tone — and come back up. The reason is mechanical: only while tightening does the winding sit firmly on the post. A string brought down to pitch from above creeps within minutes and goes flat again.

Pluck the open string firmly, but without overdriving it, and wait about half a second before reading. Every freshly struck string is briefly sharp at the attack and only settles to its real pitch as it stabilises. Read at the moment of attack and you will tune systematically flat.

On guitar, after all six strings are done, a cross-check is worth it that no tuner can perform: play an open E and an open D chord and listen for beating. Beating is the slow swelling and fading that occurs when two nearly equal frequencies meet. The slower the beat, the closer the two pitches. When it disappears entirely, the interval is pure.

One note on temperature: an instrument brought in from a cold car keeps drifting for ten to twenty minutes as it warms. Tuning is only worth doing once it is at room temperature. The same goes for newly fitted strings, which keep stretching for two or three days.

What a tuner cannot do

A chromatic tuner measures a single frequency and compares it against the equal-tempered grid. What it cannot judge is whether the instrument is in tune with itself. If all six open strings read zero cents and a chord at the fifth fret still sounds wrong, the tuner is not the problem — the intonation is.

The standard check takes two minutes: on each string compare the harmonic over the twelfth fret with the fretted note at the twelfth fret. Both should be the same pitch. If the fretted note is sharp, that string’s saddle needs to move back; if flat, forward. On a classical guitar with a fixed bridge there is nothing to adjust — there a deviation of more than about five cents points to high action or old strings.

The capo problem belongs here too. A capo presses the strings down and thereby adds tension. After fitting one the instrument is nearly always slightly sharp, especially on the thick strings. So: fit the capo first, then tune — not the other way round.

On concert pitch: this tuner works at A4 = 440 Hz and can be set to other values. That is not decoration. Play with an orchestra tuning to 442 Hz, or in historically informed performance at 415 Hz, and the reference has to move — 415 Hz sits almost exactly a semitone below 440.

Common mistakes

Tuning with vibrato. Among string players and singers this is the single most common error. Vibrato typically swings ±20 to ±50 cents; the display averages it and shows a pitch that is not sounding at the moment you read it. For tuning, hold the note straight.

Plucking too hard. A very hard attack pulls the string sideways out of rest and briefly raises the tension. On the thin strings, ten cents of deviation from attack strength alone is easy to reach.

Staring at a single value. The display always trembles a little, because a real string does not behave perfectly periodically. What matters is where the reading settles over half a second, not the value of a single measurement.

Confusing the octave. A chromatic tuner names the note, not the string you wanted. Tune the low E an octave too high and it will happily keep showing “E” — and the string will break. On guitar the open strings are 82.41 / 110.00 / 146.83 / 196.00 / 246.94 / 329.63 Hz; the displayed frequency is the more reliable check than the letter.

Underestimating ambient noise. The tuner hears everything the microphone picks up. Air conditioning, a neighbouring instrument or a conversation in the room can make detection useless. Moving closer to the microphone and finding a quiet room solves nearly every “the tuner shows nonsense” problem.

More tools in the App

Circle of Fifths Auto additionally includes circle of fifths, chord builder, scales, intervals and animated waveforms — fully offline.

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