Trouble finding your groove? Come with us as we dive into Live's Groove Pool...
Live's groove-quantising engine, the Groove Pool, can make your life a lot easier when it comes to timing. You can use it with both audio and MIDI clips to match the timing groove of one clip to another. Live's Core Library Pack contains a wide variety of groove templates in its 'Swing and Groove' folder, and this is often the quickest way to get your song in the right groove. In this month's column we'll look at how to make the most of the Groove Pool and I'll describe a number of techniques that you can use, starting with the simplest: non-destructive or 'soft' quantising.
Have a look at Live's Quantise dialogue, which you open from the context menu of any audio or MIDI clip (Command-Shift U/Control-Shift U). Both the audio and MIDI versions offer a Quantise To menu for choosing a quantising resolution between a quarter and a 32nd note along with an Amount box for selecting a quantise percentage between zero and 100 percent. Choosing zero percent results in no quantisation and choosing 100 percent moves events all the way to the closest gridline in the selected resolution. Values in between move events partway to the gridline. With MIDI notes you can also choose whether to move the beginning of the note, the end of the note or both. What more could you want? Well, here are four things you can do with the Groove Pool that you cannot do with the Quantise dialogue:
1. Instantly apply the same quantisation to multiple clips.
2. Change quantisation settings after the fact.
3. Remove quantisation at any time, not only while it's still in Live's Undo buffer.
4. Automatically apply a random offset to each event (aka humanise).
Groove Pool operations are based on groove files (file type .AGR in Live libraries). These can be derived from audio or MIDI clips, and they include all the relevant Groove Pool settings. Dragging an audio or MIDI clip to the Groove Pool will automatically convert it to a groove file (more on that later). For soft quantising, an empty MIDI clip will do because you're not really applying any groove. You do need separate groove files for different settings, however, and the easiest way to create them is to copy existing grooves by Option-dragging (Alt-dragging) in the Groove Pool and then entering the new settings.
The Groove Pool offers five parameters for each groove. The first, Base, serves the same purpose as the Quantise dialogue's Quantise To setting and the second, Quantise, serves the same purpose as the Quantise dialogue's Amount setting. The Random setting implements the humanise function, and it's usually best to use small amounts. When randomising a looping clip, you might want to consolidate it first so that each repetition of the loop receives different randomisation. The remaining two settings, Timing and Velocity, have no bearing when you're using a groove with no notes. When you want to add some velocity scaling, create a groove with a note at each of the gridlines in the chosen Base and edit those notes' velocities. With an eighth-note groove, for example, you might lower the velocity of alternate notes and then use the Velocity setting to influence the velocities of those notes in the quantised clips. The Velocity range is –100 to 100 percent, and negative settings invert the effect.
Once you've made your settings, you can apply them to any clip in either Session or Arrangement view by dragging the groove file over the desired clip or by selecting the groove from the drop-down menu in the bottom-left corner of the Clip Viewer. The latter method also works when multiple clips are selected. When you apply a groove or change its settings, you'll immediately hear the results in all targeted clips. However, you won't see any effect on either audio or MIDI unless you click a clip's Commit button. Not seeing what you're hearing can be a bit confusing, but once you do click the Commit button, you've locked in the settings. So for purposes of seeing what's going on, copy the clip and Commit the copy.
The most common use of the Groove Pool is to match the rhythmic feel of one clip to that of another. That's what the Timing setting is for, and it works in concert with both the Base and Quantise settings. First, the distance is measured from each gridline in the Base to the nearest note in the groove (if there's a tie, the earlier groove note wins). Those distances are used to adjust the notes in the clip being grooved. If you set the groove's Quantise to 100 percent, then a note's new position is determined entirely by the Timing setting, and with Timing set to 100 percent, the new position will exactly match the groove-note's position. If the groove's Quantise setting is less than 100 percent, then a note's new position will also be influenced by the note's offset from the nearest gridline. Setting Quantise to 100 percent is the norm and is usually the best choice, but notes in targeted clips that don't correspond to groove notes will then be quantised. One way around that is to split the target clip so as to apply the groove to only those notes with corresponding groove notes. You might also want to split off different kit pieces in drum clips for applying different grooves. In any case, let your ears (not your eyes) be the judge, and remember that you can change any of the Groove Pool settings in real time to hear the results.
The Groove Pool handles audio clips a bit differently from MIDI clips. It first converts each of the audio clip's Transient markers into a Warp marker and then aligns those to the groove in the same way it aligns MIDI notes. And as with MIDI, you'll hear, but not see, the effect, unless you click the Commit button. With audio, clip volume modulation is used to mimic the effect of velocity when the Velocity parameter differs from zero percent. Because applying a groove to audio moves Warp markers, the Warp mode chosen makes a big difference, and the same guidelines apply as when warping audio manually. This offers a chance to get a bit creative; for example, try Re-Pitch Warp mode on a pad or ambient clip with a few judiciously placed Transient markers.
You can extract grooves from audio clips in the same way as from MIDI clips: drag them to the Groove Pool or directly on top of another MIDI or audio clip. In this case, the audio clip's Transient markers are converted to MIDI notes in the resulting groove file, and the audio level of those transients determines the velocity of the MIDI notes in the groove clip.
Keep in mind both when deriving from and applying grooves to audio clips that you're not stuck with the transients Live applies by default. You can add and delete Transient markers by right-clicking at the desired location, and you'll often need to do this to get the best results. With drum and percussion loops, you can often spot missing or extraneous Transient markers by visually following playback of the clip, but when that's not working out, try Live's Slice To New MIDI Track option. That will produce a Drum rack with cells containing the audio slices corresponding to the Transient markers and a MIDI clip with notes to play the slices. Play the notes manually to identify multiple events and nonexistent events, insert and delete Transient markers in the original audio clip as necessary, and then extract the groove from the edited clip.