Click tracks and tempo maps: when to play to the grid and when to make the grid follow you

A click track is the metronome in your headphones. Wikipedia defines it as "a series of audio cues used to synchronize sound recordings", and traces it to early sound film, where it "originated in early sound movies, where optical marks were made on the film." A tempo map is the plan that tells the click what to do: hold 92 BPM, push to 96 for the chorus, slow into the last bar.

Together they decide one thing about your recording: does the band follow the grid, or does the grid follow the band? This guide covers both routes. The examples use Ableton Live because its manual spells out each control, but every major DAW has the same pieces under similar names.

Why bother with a click at all

The grid is what makes the rest of your DAW work. Quantising, looping a section, copying a chorus, lining up a delay to the beat, dropping in a sample: all of it assumes bar 17 is where the DAW thinks bar 17 is. Record to a click and every one of those tools behaves. Record without one and you either live without them or fix the grid afterwards.

The case against is just as real. Wikipedia notes that without a tempo map, a click track prevents the natural tempo shifts that expressive phrasing needs, and quotes the acoustician James Beament: "if you want to kill a musical performance, give the player a click track!"

What we think: both camps are right about different music. For programmed, loop-based or electronic tracks, a click is free. For a band, a singer-songwriter or a classical or Indian classical performance where tempo breathes, a rigid click costs more than it saves. The fix is not "no click"; it is a better map.

Setting up the click

In Live, the metronome switch sits in the Control Bar, with a menu next to it. The manual lists what that menu does:

• Count-in: "When set to any value other than 'None,' Live will not begin recording until the count-in is complete." One or two bars gives a player time to settle.
• Sound: "You can also change the sound of the metronome's tick." Pick something that cuts through without being harsh; a woodblock or rim sound sits better in headphones than a sine beep for most players.
• Rhythm: you can "set the beat division at which the metronome ticks". By default the tick "follows the time signature's denominator."
• Enable only while recording: the metronome "will only be audible while recording", so playback stays clean.

Three practical habits that the manuals don't tell you:

1. Subdivide slow songs. At 60 BPM a quarter-note click leaves a second of silence to drift in. Eighth notes give the player more to hold onto.
2. Try the click on 2 and 4. A player who knows the song often prefers a click on 2 and 4, which feels like a backbeat instead of a drill.
3. Keep the click out of the mics. Leaking headphones on a quiet acoustic take print the tick into the recording. Turn it down, or use closed-back headphones.

Building a tempo map

If the song should change speed, write the change before you record. In Live, the manual puts it plainly: "the song tempo is just another automated control." To edit it, "unfold the Main track in Arrangement View" and choose the tempo envelope. Two boxes set the range: "The left box sets the minimum, and the right box sets the maximum tempo displayed, in BPM."

From there it works like any other automation:

• A step (a jump from one value to another at a bar line) is a section change: verse at 88, chorus at 92.
• A ramp (a slope between two points) is an accelerando or a ritardando: the last four bars slowing from 92 to 80.
• A pause is easier as a bar of a different time signature or a held step than as an extreme ramp.

The click follows the map, and so does everything locked to the grid: MIDI parts, warped audio, tempo-synced delays. That is the point. You get a song that breathes and an arrangement you can still edit.

A rule of thumb: small, deliberate changes (a couple of BPM into a chorus) are often felt rather than heard. Big ones should be audible choices. If you can't say why the tempo moves at a given bar, it probably shouldn't.

The other route: let the grid follow the band

Sometimes the right answer is to record the performance as it happens and fit the grid to it afterwards. Live has tools for both live following and after-the-fact fixing, described in its warping chapter:

• Warping "lets you treat audio as though it were elastic, enabling seamless time-stretching and tempo synchronization."
• Following live players: Live can "align a Set with external sources that aren't locked to a single tempo, such as live musicians", including through Tempo Follower, and Phase Nudge buttons "temporarily speed up or slow down Live's playback to match any tempo changes."
• Making a recording lead: "When a clip is set to Lead, the Set plays back at the tempo determined by the clip's Warp Markers." In other words, place warp markers on the beats of a free performance and the whole project's grid bends to it.
• Warp From Here commands run Auto-Warp from a marker onward; the manual notes that the Straight version "works best for samples that have no tempo variations", so use the plain version on a free-time take.

This route suits a solo performer, a live recording, or a jam you want to build on. It costs time: someone has to check every warp marker. It also means the first take sets the tempo for everything you add later, which is a feature if the take is good.

Which to use

Our analysis across these sources: the click and the free take are not opposites. Both end with a tempo map. The only question is whether you draw it before the performance or recover it from the performance afterwards. For drum parts and groove and quantise work, either way gives the grid you need.