About

This is not a toy. Most browser-based metronomes rely on the standard JavaScript setInterval or setTimeout functions. In a single-threaded environment like a web browser, these timers are unreliable; they drift when the interface re-renders, when garbage collection runs, or when you switch tabs. For a professional musician, a drift of even 20 milliseconds disrupts the pocket.

The Metronome Online Enterprise engine solves this by bypassing the main thread's clock entirely. It utilizes the Web Audio API Scheduler pattern. We schedule audio events into the hardware's buffer ahead of time (Lookahead Architecture). This guarantees sample-accurate timing regardless of CPU load. This tool effectively turns your browser into a dedicated hardware timing device.

Beyond accuracy, we address the reality of practice. The integrated Speed Trainer automates the process of building muscle memory by incrementally increasing tempo over time. The Polyrhythm Generator allows for the visualization and auralization of complex ratios (like 5:3 or 7:4), essential for modern jazz and progressive metal performance.

Formulas

To ensure drift-free timing, we use the formula for lookahead scheduling. The time for the next note is calculated relative to the Audio Context's internal clock, not the wall clock.

t_next = t_current + (60BPM × 4Resolution)

When calculating Polyrhythms (e.g., x:y), the secondary pulse interval is derived as:

Interval_poly = Interval_main × (yx)

For the Speed Trainer, the Linear Acceleration formula over n bars is:

BPM_new = BPM_start + (Increment × floor(BarsPlayedBarStep))

Reference Data

BPM Range	Italian Term	Musical Character	Genre / Reference
20 − 40	Grave	Slow, solemn, heavy.	Doom Metal, Drone, Ambient.
40 − 60	Largo	Broad, very slow.	Dubstep (Half-time), Ballads.
60 − 66	Larghetto	Rather broad.	R&B, Trip-Hop, Downtempo.
66 − 76	Adagio	At ease, slow.	Classic Soul, Reggae (One Drop).
76 − 108	Andante	Walking pace.	Hip Hop (Boom Bap), Funk.
108 − 120	Moderato	Moderate speed.	Pop, Modern Rock, House (Deep).
120 − 140	Allegro	Fast, bright.	Techno, Trance, Disco.
140 − 168	Vivace	Lively, fast.	Dubstep (Standard), Trap.
168 − 200	Presto	Very fast.	Drum & Bass, Punk Rock, Bebop.
200 +	Prestissimo	As fast as possible.	Speed Metal, Hardcore, Free Jazz.

Frequently Asked Questions

Bluetooth devices inherently introduce 100-300ms of latency due to signal compression and transmission. This is a hardware limitation, not a software one. For precision practice, we strongly recommend using wired headphones or the device's built-in speakers.

Lookahead is a technique where the metronome "schedules" audio clicks a split second before they actually happen. Instead of asking the processor to "Play Now" (which can be delayed if the processor is busy), we tell the audio hardware "Play at timestamp X". This ensures the click happens exactly on the grid, even if the visual interface lags.

Polyrhythms involve playing two conflicting rhythms simultaneously. Select a base Time Signature (e.g., 4/4) and then enable the Polyrhythm toggle. Select a ratio like "3:2". You will hear the main beat (4 clicks) and a secondary beat (3 clicks evenly spaced across 2 main beats). Use the "Poly Vol" slider to mix the levels.

Yes. Use the "Setlist" feature. Configure your BPM, time signature, and sounds, then click "Add to Setlist". These are saved to your browser's Local Storage, so they will persist even if you close the page.

The Speed Trainer helps build technique. Instead of manually stopping to increase speed, you can set it to increase by, for example, 5 BPM every 4 bars. This forces you to adapt to faster tempos gradually without breaking your flow.