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Re-slicing Audio In Ableton Live

Ableton Live Tips & Techniques
Published November 2017
By Len Sasso

1: Notes beginning with C1 trigger Simpler slices at the Start marker and active (orange) transients. The resampled audio clips at the right show the effect of playing the two Simplers with the same MIDI clip.1: Notes beginning with C1 trigger Simpler slices at the Start marker and active (orange) transients. The resampled audio clips at the right show the effect of playing the two Simplers with the same MIDI clip.

We examine the creative possibilities of Re-slicing audio in Ableton Live.

This month we’ll have a look at Re-slicing, a process featured in the Ableton One Thing video by Ben Casey (ableton.com/one-thing). The ‘one thing’ is that changing the Transient Sensitivity of a Simpler in Slice mode changes which slices of audio are triggered by a MIDI clip, while preserving the rhythm with which the slices are triggered. Applied to a sliced drum clip, for example, you might get different kit pieces playing the rhythm of the notes in the MIDI clip. Re-slicing is useful for most kinds of material — it doesn’t necessarily need to be rhythmic and it can be tonal or not. With tonal clips, however, the harmonic rhythm (chord changes) will usually not be preserved. That can be surprisingly useful.

The Setup

When you load a sample into Simpler and select Slice mode, Simpler inserts the same transients that Live detects when you Warp an audio clip. In fact, if you drag the clip into Live and edit the transients before loading it into a Simpler, the Simpler will use the edited transients. But there is no need to do that because you can add, delete and move transients in Simpler’s Sample Display window. Simpler’s transients are marked by vertical lines with a triangle on top. Click-drag on any transient marker to move it, double-click to delete it and double-click between transient markers to add one. With most clips, you’ll want to make minor adjustments to transient markers that have been placed later than the sound actually starts. That can lead to a glitch at the end of the preceding slice, which you can eliminate by dragging the transient a little to its left.

Transients are differentiated by colour: orange for active, grey for inactive and white for user-added, which are always active. Slices are delineated by the sample-start marker and each active transient marker. At 100 percent Sensitivity all transients are active. As you lower Simpler’s Sensitivity, more and more transients become inactive (turn grey), and the surrounding slices merge. In the drum-clip example, notes triggering merged slices will produce multiple drum hits.

Slices are triggered by notes starting at C1 (MIDI note number 36). When a transient becomes inactive its trigger note and all higher notes will either trigger a slice at a later transient or will exceed the slice count and go silent. Screen 1 shows the first nine transients of a Simpler with 100 percent Sensitivity. C1 triggers the slice at the Start marker, and C#1 to G1 trigger the slices at the second to ninth transient markers. (The first transient marker has been automatically disabled because it is too close to the Start marker — moving it to the right will re-enable it, creating a new slice.) In the Simpler at the bottom, the sensitivity has been reduced to 76 percent, deactivating four transients. Notes C1 through D#1 now trigger the ‘double’ slices between the remaining active transients. Both Simplers are in Trigger mode, which means that each slice plays until it ends. In Gate mode, slices play only as long as the MIDI note is held. In Mono Playback mode triggering a new slice terminates the currently playing one, whereas in Poly mode slices can play simultaneously. Trigger and Mono are the easiest choices to work with when re-slicing, but the other modes can be useful. 2: A  seven-chain Instrument Rack houses Simplers with different Sensitivity settings for the same sliced sample. Play notes between C-2 and F#-2 as keyswitches or create a  clip envelope to select different Simpler chains.2: A seven-chain Instrument Rack houses Simplers with different Sensitivity settings for the same sliced sample. Play notes between C-2 and F#-2 as keyswitches or create a clip envelope to select different Simpler chains.

Finding The Groove

To get to grips with re-slicing, find a rhythmic audio clip a few bars long and drag it to the Instrument/Sample drop area of an empty MIDI track. This will create a Simpler holding the clip. Click the Slice button in Simpler’s bottom-left corner to put it in Slice mode and then play notes starting at C1 to audition the slices. This is a good time to fix glitches at the ends of slices as described above, and you may occasionally want to delete a transient marker to eliminate a very short slice. Next, record or step-enter a MIDI pattern to create a nice groove from some of the slices. This is where the fun starts: with the MIDI pattern looping, use your computer keyboard or mouse to reduce Simpler’s Sensitivity and listen to how the loop changes while the groove is preserved. I like to select the Sensitivity control and use the Up and Down Arrow keys for that even though it usually takes a few steps for the loop to change.

3: At the top, a  Max For Live Euclidean-style step sequencer provides trigger notes and a  Max For Live LFO selects chains at random. Below, delay-based effects process three of the seven Simpler chains.3: At the top, a Max For Live Euclidean-style step sequencer provides trigger notes and a Max For Live LFO selects chains at random. Below, delay-based effects process three of the seven Simpler chains.The easiest way to capture the result is to record Simpler’s output as you change the Sensitivity setting, but then you’re left to ferret out the keepers from the junk and to slice the recorded audio clip accordingly. Alternatively, each time you find a Sensitivity setting that works, you can record a new audio clip or Freeze the Simpler track and then copy the frozen MIDI clip to an audio track. If you use freezing you need to make a change to one of Simpler’s parameters each time you unfreeze in order to force Simpler to create a new file the next time you freeze. (I click the Filter button on and back off.)

Envelopes & Automation

Automating Simpler’s Slice Sensitivity control would be a great way to change loops without going through the bother of recording or freezing, but this parameter is not available for mapping or automation. As a workaround you can use an Instrument Rack with a separate Simpler for each Sensitivity setting and then automate the Rack’s Chain Selector. Here are the steps to set that up:

  • Create a Simpler track holding your sliced loop and MIDI groove clip.
  • Enclose the Simpler in an Instrument Rack (CMD-G) and label the Rack’s first chain ‘100%’.
  • Duplicate that chain a few times. Seven chains fill the visible part of the chain list, and that’s usually more than enough.
  • Open the Rack’s Chain Selector editor and give each chain its own zone.
  • Map the Chain Selector to one of the Rack’s Macro knobs and set its maximum value to the number of zones — seven in the Screen 2 example. This gives you a separate zone for each chain (zones 0 to 6) along with an additional zone (7) that selects no chain, which you can use to insert silence. I like to map the Macro knob to an out-of-range key zone such as C-2 to G-2 to make it easy to change zones on the fly.
  • In all but the first chain, use Simpler’s Sensitivity control to find a loop you like and then rename the chain.

Now start your MIDI groove clip playing and use the keys in the mapped range to change Simplers. With a little attention to the rhythm, changing zones almost always sounds good. Playing the slice triggering notes and the Chain Selector notes at the same time can be a bit of a challenge, but once you’ve recorded the trigger notes you can easily overdub or draw in notes, a clip envelope or automation to control the Chain Selector. Screen 2 shows the transport settings for overdubbing in Session and Arrangement view.

One thing to watch out for with lower Sensitivity settings is that slices from different Simplers may overlap. The quick fix for this is to change the lower Sensitivity Simplers to Gate mode so that slice playback stops at the end of the MIDI note. Another option is to move transients to shorten the offending slices.

Here are a couple of ways to get creative with your re-slicers. Use Max For Live MIDI effects to trigger slices and select Simpler chains. At the top of screen 3, Circle Step Sequencer triggers a step each time the rotor hits an active position (dark dot) on the circle. At the same time, the MIDI LFO randomly changes chains in the Simplers Rack.

Adding effects to a few of the Simpler chains is another way to spice things up. At the bottom of screen 3, different delay effects are added to three of the Simpler chains. Because any chain is active for only a short period and most chains don’t have effects, the results are not overbearing.

Published November 2017