Beat Slicer for Elektron Octatrack

Record freely, set the original BPM, and create beat-spaced slices without planning an exact recording length.

Module version 0.1.66-experimental. Base firmware: 1.40C.

About this module

Beat Slicer allows users to record audio freely without having to determine the recording length in advance. You only need to start recording on a downbeat and know the original BPM. There is no need to plan the recording length, stop on a bar boundary, or trim the audio to fit a fixed number of slices.

• Record without planning an exact number of bars; stop between bar boundaries.
• Use the original sample BPM or the captured project BPM.
• Choose 1, 2, 4, 16, 32 or 64 beats per slice.
• Create grids for Flex, Static and completed recorder buffers during playback.

How to use it

1. Start recording on a downbeat. Begin recording on the first beat of a bar so the audio is aligned with the musical grid.
2. Record for as long as you like. Perform, improvise, or capture live audio without worrying about recording an exact number of bars. Stop recording whenever you are finished, even in the middle of a bar.
3. Set the original BPM. Enter the tempo at which the audio was recorded so Beat Slicer can calculate the duration of each beat.
4. Choose the number of beats per slice. For example, selecting 4 beats per slice divides the recording into 4-beat segments. Any remaining audio becomes a shorter final slice.
5. Sequence and play back the slices. Trigger the slices at the appropriate beat intervals to reconstruct the original performance, preserving its musical timing without manually trimming the recording.
6. When using PROJECT BPM with a different sample tempo, turn off track time-stretch or set the sample ATTR BPM to the audio's actual recorded tempo to avoid unintended stretching. Beat Slicer does not change playback settings.

Controls

BPM SOURCE

use the sample ATTR BPM or the project BPM captured at preview. No silent fallback.

SPACING

beat spacing, anchored at trim start. A beat is a quarter note.

Compatibility notes

• Needs the Modwerk base loaded over USB (beta). Card firmware cannot include it.
• Recording duration remains subject to Octatrack memory; a grid can contain at most 64 slices. Increase beats per slice if the grid would exceed this limit.
• The grid starts at the current trim start. A final fragment shorter than the stock 64-frame minimum is included in the preceding slice.
• Recording must be stopped for the buffer being edited; unrelated recording and pattern playback may continue.
• Not offered together with Recorder Loop Fix 0.1.0: that module can make recorder-buffer slice 1 miss, also with stock CREATE SLICE GRID and without Beat Slicer (sambanks/octabam#908).
• Exact metadata grid only: no PCM analysis, smoothing or click-free playback claim. No project or sample-settings save is implicit.
• Not yet tested on the MKI. Slices kept through a project save and a power cycle, Static machines and recorder buffers were not run on this exact package (an earlier build was, by the author).
• While the CREATE BEAT GRID popup is open its drawing takes about 6 % of the ColdFire (owner's MKII); the frame interrupt was unaffected and no machine render was skipped.

Test evidence

On the owner's MKII over USB (27 Oct 2026), on a development twin of the beta base with the sample-editor service, as two timed trials that rolled back: the exact package 6650ef77 listed CREATE BEAT GRID, sliced a Flex sample at 2 and 4 beats from SAMPLE BPM and showed PROJECT BPM, re-sliced while the pattern played, left the slices alone on NO, passed the base self-test and was gone after the rollback. Earlier packages ran on the author's MKII with Flex, Static and recorder buffers. Save/reboot persistence, Static and recorder sources on this package, the MKI and a static cycle bound remain open.