Tune an instrument

The Tuner tab is a microphone tuner. It reads a steady note to within a cent, from a 5-string bass's low B upwards. Nothing is recorded or uploaded; pitch is detected in the browser and the microphone is released when you press Stop, switch tab or leave the page.

Tune up

1. Switch to the Tuner tab (opening /app/bpm-forge#tuner lands there directly). The metronome stops so its clicks do not reach the mic.
2. Press ▶ Start tuner and allow the microphone.
3. Play one clear note and let it ring. The nearest note, the frequency in Hz and the deviation in cents (to a tenth) appear.
4. Watch the cents bar: left of centre is flat (tune up), right is sharp (tune down). Inside ±5 cents it turns green and reads ✓ In tune.

no signal means the tuner hears nothing usable — check the mic permission and play a single note without chords or heavy distortion.

Reference A4

The tuner is referenced to A4 = 440 Hz unless you change it. Under Reference A4, pick 442 or 443 — what many orchestras and pit bands tune to — or type any value from 430 to 450 Hz. The current reference shows under the reading and is remembered.

Transposing instruments

In Chromatic, Show notes for switches the display to what a B♭, E♭ or F instrument reads: a concert A shows as B on a B♭ trumpet or clarinet, F♯ on an E♭ alto sax, E on an F horn. The cents don't change.

Instruments and tunings

Chromatic (the default) shows the nearest note for any pitched source — voice, brass, winds, piano. The instrument presets add a string strip that highlights the string you are playing and a Tuning picker with the common tunings for that instrument. If a note is more than a quarter-tone from every string, the display says which note is actually sounding and which way to turn the peg.

• Guitar — standard, Drop D, E♭, open G, DADGAD and more
• Bass — 4-string, 5-string (low B), Drop D
• Ukulele — standard (high G), low G, baritone
• Violin, Viola, Cello, Mandolin — fifths tunings
• Banjo — open G, double C
• Drums — see below

Bass, cello and drums listen over a longer window, so the lowest notes read as steadily as the high ones.

Reference tones

Tap a string in the string strip to hear its target pitch, and tune by ear. In Chromatic, ♪ Reference A4 plays A at the current reference. The tuner stops listening while a reference sounds.

Custom tuning

Under Custom tuning, each string has its own dropdown with the note and octave — a string can go down or up an octave. Change any string and the active tuning forks into a live Custom tuning: a Custom pill appears in the Tuning row and is lit while it is in use. It is remembered per instrument — and, when you are signed in, with your account.

Strobe view

Switch Standard to Strobe to swap the cents bar for a strobe display that drifts while you are off and freezes when you land — easier to read at a glance than a needle. It shows the same reading as the cents bar.

Drums

Pick Drums and choose the drum — kick, snare, toms, floor tom; each pill shows its target range in Hz. Hit the head: the bar shows where the drum sits inside the range (centre = the middle of the range), it turns green inside it, and the line under the note says below range — tighten or above range — loosen.

Release and chime

• Release (Fast, Mid, Slow) sets how long the reading lingers after the note stops.
• In tune within (±1, ±2, ±3, ±5 ¢) sets how close counts as in tune — ±5 is relaxed, ±1 is for the last careful pass.
• In-tune chime (On / Off) plays a short tone when you land in tune. The tuner stops listening while it rings, so the chime can't tune itself.