How to make a click track follow a recording that speeds up and slows down
A band recorded without a click speeds up and slows down slightly, so a metronome at one fixed BPM drifts away within a minute. The fix is a beat grid: the exact time of every beat in the recording. Once a song has a beat grid, the click is placed on each real beat instead of on a fixed tempo, so it stays with the recording from the first bar to the last.
Fixed BPM vs a beat grid
A fixed BPM assumes every beat is the same length. Real performances aren't: the chorus pushes, the bridge relaxes, and over three minutes the difference adds up to whole beats. A beat grid stores the time of each beat, so the click can follow every push and pull.
Two ways to get a beat grid
- Beat detection (AI): software analyses the audio and finds every beat and downbeat. Fast, and it usually finds the sections too.
- Tap along: you tap on each beat while the song plays, and the taps are fitted into a grid. No AI needed and you stay in control.
Check the grid
- Play the song with the click from the top.
- Listen at the start, the middle and the end — drift shows up late.
- Check beat 1: the strongest beat should fall on the first click of each bar.
- Fix the start (beat 1) if the whole grid sits one beat off.
Beat grids in Metronome Map 2
Every way of adding audio to a song in Metronome Map 2 ends with a beat grid, so the click, loops, count-ins and cues follow the recording.
- AI: attach your audio file and let AI find the beats, downbeats and sections and split the stems. Free for 1 whole song a month.
- Tap along: attach the file without AI and tap on every beat while it plays; the app fits your taps into a grid of beat times.
- Set beat 1 on the waveform if the bar starts in the wrong place.
- Changing a song's BPM by hand asks first, then clears the recorded beats, so the new tempo really takes effect.
Clicks are scheduled ahead of time on the audio clock, so they stay locked to the audio even on a long song.
Questions
Why does my metronome drift away from the song?
The recording isn't at one exact tempo. Give the song a beat grid so the click follows each beat instead of a fixed BPM.
Is AI beat detection accurate?
For most pop, rock and worship songs it is very close. Always check beat 1 and listen to the end of the song.
Can I make a beat grid without AI?
Yes. Tap along on every beat; Metronome Map 2 fits the taps into a grid and keeps it as beat times.
Does it work with YouTube?
Yes, by tapping along to the video. AI doesn't analyse YouTube audio.
Try it in Metronome Map 2
The metronome that follows your song: song map, cues and count-ins, AI beat grid and stems, notes that zoom and set lists. Free on Android; iPhone and iPad beta on TestFlight.
