Speed trainer metronome for any tempo range

What a speed trainer does, and why the change has to land on the bar line

A speed trainer is a metronome that changes tempo on its own. You give it a start tempo, a target, a step and a stage length, then you play the same lick, riff or scale pattern while the click climbs (or falls) in small increments. It replaces the ritual of stopping, reaching for the screen, adding 2 BPM and losing your place. In practice that ritual is why most players raise the tempo in lazy 10 BPM jumps: small steps are simply too much bother by hand.

The one thing a speed trainer must get right is where the change happens. A riff has a shape that lasts a bar or a short group of bars. If the click accelerates on beat 3, the second half of your phrase is played at a different tempo than the first, you cannot judge whether it was clean at either tempo, and your hands receive a contradictory signal about the pulse. A tempo change in the middle of a bar is worse than no trainer at all.

This metronome evaluates the plan only at the start of a bar. In bars mode a stage lasts exactly N bars, counted from its own first downbeat. In seconds mode the app checks on every bar line whether the current stage has lasted at least N seconds; if it has, the new bar starts at the new tempo, and if not, one more bar is played at the current tempo. A 30-second stage at 130 BPM in 4/4 (one bar is about 1.85 s) therefore runs for 17 bars, roughly 31.4 s, and the switch still falls on beat 1. Because the clicks are scheduled ahead of time through the Web Audio API rather than a JavaScript timer, the new tempo starts exactly where the old bar ends, and it keeps doing so with the tab in the background.

BPM always refers to the beat unit of the time signature, the note in the denominator. In 4/4 at 200 BPM the click is a quarter note; in 7/8 at 240 BPM it is an eighth note, and a stage of “4 bars” is 28 eighths. The trainer works with every meter the odd time metronome supports, including grouped 7/8 and 11/8.

Setting up a run

Every field in the trainer panel, and what it does:

• Start BPM (1 to 1000): the tempo of the count-in and of the first stage. Pick a tempo at which you can play the passage four times in a row without a single flubbed note, not the tempo you wish you had.
• Target BPM: where the run ends. A target above the start gives an ascending run, a target below gives a descending one, and a target equal to the start gives a single stage for endurance work. The Swap button exchanges start and target, so a cool-down is one tap away from the warm-up you just played.
• Step (1 to 100 BPM): how much the tempo changes per stage. The direction is taken from start and target, so you never type a minus sign. If the step does not divide the range, the last stage is clamped to the target.
• Change every N bars or N seconds (1 to 600): the length of a stage. Bars mode is the musical choice for riffs and licks; seconds mode is convenient for scales or long-tone exercises where the phrase length does not matter. Seconds are rounded up to the next bar line.
• Count-in bars (0 to 8): bars at the start tempo before stage 1. One bar is enough if your hands are already on the strings; use two if you start the click and then pick up the guitar; use zero when you launch with the Space key.
• Go back down to the start after the target: after reaching the target, the plan walks back down to the start without repeating the target stage. 180→200→180 is one continuous wave.
• At the end: Stop, Keep playing at the final tempo, or Loop the plan from the first stage.
• Stage chime: a short extra sound on the first beat of every new stage, so you know the tempo moved without looking at the screen. Switch it off if it distracts you.

Recommended values for three situations

1. Learning a new lick. Start slow, often at 50 to 60 percent of the goal tempo, target the goal, +5 BPM every 8 bars, count-in 2, chime on, stop at the end. Eight bars give you four repetitions of a two-bar lick per stage, which is enough to hear whether it is settling in. The built-in Warm-up preset uses the same 80→120 in +5 steps every 8 bars, with a one-bar count-in, and keeps playing at 120 when it arrives.
2. Pushing a plateau. Work in a narrow band of 10 to 20 BPM just under your ceiling: 220→240, +1 every 4 bars, count-in 1, stop at the end. The whole run takes about a minute and a half, so do it two or three times with a short rest between. The single-BPM steps are the point: your hands do not notice a 0.5 percent change, and twenty of them add up.
3. Endurance. Start equals target, for example 120, one stage of 300 seconds, stop at the end. The trainer becomes a timer that plays the click, and the session lands in your history with its length. This is how the built-in Endurance preset is set up.

Worked examples

The arithmetic is simple enough to do in your head. Stages = range ÷ step + 1 when the step divides the range (the start and the target both count). Bars = stages × bars per stage, plus the count-in. One bar lasts beats × 60 ÷ BPM seconds; in 4/4 at 220 BPM that is 4 × 60 ÷ 220 ≈ 1.09 s. Add the bars of every stage at its own tempo and you have the run time. All figures below are for 4/4 with a one-bar count-in.

The 220→240 run has 21 stages because 220, 221 … 240 is twenty-one values. At 4 bars each that is 84 bars; each bar is between 1.09 s and 1.0 s, so the run lasts about 88 seconds plus the count-in. The 160→200 run has the same number of stages and bars, but the bars are longer at the lower tempo, which is why it takes almost half a minute more.

The descending 120→80 example is a cool-down: nine stages of eight bars, each bar getting longer as the tempo falls, close to three minutes in total. The back-to-the-start example goes 180, 185, 190, 195, 200 and then 195, 190, 185, 180 without repeating 200: nine stages, 36 bars, under a minute. With “Loop” at the end it becomes a continuous wave that is excellent for alternate picking, because relaxing on the way down is as much a skill as holding on at the top.

During the run

The stage panel shows the current tempo large, the stage number out of the total, the next tempo and the bars (or seconds) remaining in the current stage. During the count-in it says so. Watch the remaining bars only if you need to; the chime tells you the same thing without taking your eyes off the fretboard.

What the chime means. It sounds on beat 1 of the first bar of a new stage. If you hear it while you are in the middle of a phrase, your phrase is not lined up with the bar, or the stage length is not a multiple of your phrase. A two-bar riff needs 2, 4 or 8 bars per stage, never 3 or 5.

• [ and ] jump to the previous or the next stage. Use ] to skip the easy opening stages of a preset, and [ to repeat a stage that fell apart instead of letting the run drag you further up.
• Space pauses and resumes; the stage is kept, so a phone call does not send you back to the start. S stops the run.
• Restart begins again from the count-in at the start tempo, useful after you change a fingering and want a clean comparison.
• F opens the fullscreen focus mode, and the screen is kept awake where the browser supports it (not in Firefox). On iOS, remember that locking the screen or letting another app take over the audio pauses the click.

When a run ends or you stop it, a session longer than 10 seconds is added to the local history with its time, bar count and BPM range. The history keeps the last 50 sessions, which is plenty to see whether the top of your band has moved over a month.

Presets

Four built-in presets cover the situations above:

• Warm-up: 80→120, +5 BPM every 8 bars, keeps playing at 120 when it gets there.
• Alternate picking: 160→200, +2 every 4 bars, stops at the target.
• High-speed guitar: 220→240, +1 every 4 bars, stops at the target.
• Endurance: 120 BPM held for 5 minutes (one stage of 300 seconds).

Your own presets work the same way: set the fields, save under a name, and the preset is stored in your browser next to the built-ins. You can rename it, duplicate it to try a variant without losing the original, and delete it. Duplicating a built-in gives you an editable copy, so “High-speed guitar” becomes “High-speed guitar copy” at 230→250 in a few seconds. Presets never leave the device unless you send someone a share link, which carries the current plan in the URL. A sensible set for a guitarist is one preset per technique: a picking run in sixteenths, a legato run in triplets, a palm-muted riff in eighths. The guitar practice page goes through that routine, and the main metronome is where you set the subdivision and the click sound the trainer will use.

Common mistakes

• Steps too big. +10 every 4 bars over a 20 BPM band is three stages, not a gradient. Keep the step at or below about 2 percent of the tempo: +2 around 100 BPM, +4 around 200. For the last 10 BPM before your ceiling, use +1.
• Ignoring clean speed. The trainer cannot hear you; it will happily take you to 240 while you are flailing. Decide before the run what counts as clean (no missed notes, even dynamics, no tension in the picking hand) and press [ the moment a stage does not meet it. The tempo of that stage is tomorrow’s target, not today’s.
• No descending phase. Speed practice that only goes up teaches you to grip harder as the click rises. Use the back-to-the-start option, or finish with a 120→80 cool-down run; the descent shows you how much tension you were carrying.
• Never recording. The history stores time and BPM range, not how it sounded. Record thirty seconds at your top stage once a week with your phone and listen back the next day. Notes that felt fast usually sound rushed.
• Changing several variables at once. New pick, new fingering, new subdivision and a new tempo range in the same session tell you nothing. Change one thing per week and keep the trainer plan identical so the numbers stay comparable.
• Confusing the beat unit with the note you play. Sixteenths at 120 BPM are the same speed as quarter notes at 480. Set the subdivision to 4 and train at 120 rather than pushing the BPM into the hundreds, unless you actually want to feel the pulse that way.

Frequently asked questions

Can the speed trainer start above 200 BPM?

Yes. Start and target accept any tempo from 1 to 1000 BPM, so a run from 220 to 240 or from 260 to 280 is set up exactly like one from 80 to 120. The built-in High-speed guitar preset is 220 to 240 in +1 steps every 4 bars.

What happens when the step does not divide the range evenly?

The last stage is clamped to the target, so you never overshoot. 220 to 240 in steps of 3 gives 220, 223, 226, 229, 232, 235, 238 and then 240 as the final stage.

Does the seconds mode cut a bar in half when the time runs out?

No. When a stage is set in seconds, the app checks at the start of every bar whether the stage has lasted at least that long, and only then switches. A stage may therefore run a little longer than the number you typed, but the tempo never changes mid-bar.

Can I train downwards, from a fast tempo to a slow one?

Yes. Set the target lower than the start and the trainer subtracts the step at every stage, for example 120 to 80 in −5 steps. Turn on “Go back down to the start after the target” if you want one run to go up to the target and back down to the start.

What happens when the run reaches the target?

You choose in the “At the end” setting: Stop the click, Keep playing at the final tempo for as long as you like, or Loop the whole plan from the beginning. Sessions longer than 10 seconds are saved to the local history either way.

How do I share a training plan with a student or a bandmate?

Use the share link. The URL encodes tempo, time signature, accents, grouping, subdivision and every trainer field, so whoever opens it sees the same plan ready to start. Nothing is uploaded; the settings live in the link itself.

Is my plan still there after I close the tab?

Yes. Trainer settings, your saved presets and the session history are stored in the browser (localStorage), without an account or cookies. Clearing site data for this page removes them, so save a share link of anything you would hate to lose.

Does it work in odd meters like 7/8 or 5/4?

Yes. A stage counts bars of whatever time signature you set, so “every 4 bars” in 7/8 means 28 eighth notes. Remember that BPM refers to the beat unit of the signature: in 7/8 at 240 BPM the click is an eighth note.