Four picks from our free-plugin list: IVGI for saturation, Cramit for drum textures, Ephemere for changing percussion and TetraOP for hands-on synthesis.
September's selection comes from our free-plugin list: Klanghelm IVGI, Sixth Sample Cramit, Inear Display Ephemere and Tiagolr's TetraOP. These are four tools for working on the sounds inside a part, whether that means changing a recording you already have or building something from an oscillator.
A rhythm can have all the right notes and still feel unfinished. Perhaps the bass loses its definition when the drums enter. Perhaps the percussion repeats so exactly that you start hearing the loop boundary. Adding another part is one answer, but it also gives the arrangement another thing to accommodate. Sometimes there is more to explore in the sounds already playing.
That is the reason for this month's combination. The two effects let you revisit an existing recording; the two instruments give you control over how individual notes develop and vary. These are monthly picks, not September release announcements. Product details are linked to the developers' pages, and the examples below are suggestions to try in your own projects.
IVGI: give an existing part more harmonic detail
Klanghelm IVGI is a free saturation and distortion effect for Windows and macOS. It responds to the incoming signal, with controls for the symmetry and frequency dependence of the saturation. The useful question here is how far you can change a part's texture while keeping the performance you liked.
Try a bass phrase containing both held notes and shorter accents. Turn up the drive gradually, then reduce the output level so bypassing the effect doesn't produce a large jump in loudness. Listen with the drums playing. Added harmonics may help you follow the bass, but listen for changes to its weight and the distinction between notes too.
Compare the quietest phrase with the loudest one before committing. Because the input affects the result, a setting chosen on one section can behave differently elsewhere. If only a few accents need more edge, try adjusting those moments rather than driving the entire performance harder.
It is an appealing kind of experiment because the source remains recognisable. You can keep the notes, timing and phrasing, and decide how much roughness that particular part can carry.
Cramit: bring the quieter parts of a drum recording forward
Sixth Sample Cramit, made with Integraudio, combines three-band upward and downward compression and expansion with distortion before or after the dynamics processing. The standard edition is free; Platinum is a separate product.
A drum recording is a useful place to start because there is often a second rhythm hiding below the main hits: room reflections, cymbal decay and softer strokes. Bringing those details forward can change how continuous or crowded the groove feels, even when the MIDI or audio timing stays exactly the same.
Try a short passage with a clear pause after the snare. Work on the dynamics first, then compare the distortion before and after that processing. Keep the playback level similar while switching. Listen to the pause: does it still feel like a break, or has the tail become another event?
If the processed version has an interesting texture but loses too much punch, try blending some dry signal back in. The point is to find a relationship between the main hits and what surrounds them. More audible detail is useful when it contributes to that relationship; it can also make a deliberately sparse beat feel unnecessarily busy.
Ephemere: vary percussion without rewriting the pattern
Inear Display Ephemere has twelve FM percussion engines, mapped across an octave. Its user guide describes randomisation ranges for individual synthesis parameters and a trigger probability for each sound. Those give you two separate decisions: how a hit changes and whether it happens at all.
Start with one percussion voice against a fixed kick and snare. Keep its MIDI rhythm simple and introduce a small randomisation range on one parameter. Let it run for several passes before changing anything else. You are listening for a useful range of variation, including the least convincing result it produces.
Then try lowering the trigger probability on a secondary hit. Keep an important accent certain while allowing a quieter answering hit to come and go. The pattern can retain its identity without every repetition containing the same events.
Record several passes to audio when a pattern begins to work. Choose a phrase, then listen to where it joins the next one. You can keep a surprising detail and still edit an awkward transition. Randomisation supplies possibilities; choosing which ones belong together remains part of writing the track.
TetraOP: build a patch around a short phrase
Tiagolr's TetraOP combines four wavetable operators with FM and ring-modulation routing. It is open source. The project notes also describe its limitations, including the absence of a wavetable editor and preset browser. This is a pick for spending time on a patch.
Use a two-bar phrase with a few gaps and keep it playing while you work. Begin with a simple routing, then change one modulation connection. Listen to the attack and the sustained portion separately. A bright onset that settles quickly can serve a very different role from a tone that stays dense for the whole note.
Once something interests you, play the phrase an octave higher and lower. That is a useful way to find the register where the patch belongs before writing a longer part around it. Shorten some notes as well; the patch needs to work with the articulation of the line.
Save a few distinct versions as you go. Returning to an earlier, simpler patch can help when a sequence of individually interesting edits has made the original phrase harder to hear.
An experiment for a loop that feels too repetitive
Take eight bars from a project and duplicate them. Leave the first eight alone. In the second eight, choose one supporting part to change, keeping the main melody and drum pattern intact. You might make a quiet texture more audible, replace a repeated percussion sample or write a different sound for the same notes.
Now play the full sixteen bars without touching the controls. Listen for whether the change gives the second half a reason to exist. An obvious transformation can work, but a smaller one may suit the track better. You don't need the listener to identify the processing; you need to hear whether the phrase holds their attention.
If the change works, decide where to introduce it. It could arrive immediately at bar nine, build over four bars or appear only on the last beat before the next section. Those choices are worth trying before reaching for another plugin. The same sound can feel like a new section, a gradual build or a brief fill depending on its placement.
Keep a dry version available while making that decision. After hearing the changed version repeatedly, familiarity can make it feel necessary. Returning to the original is a useful reminder of what the part was doing before you started, and whether the experiment has actually helped it.
Download links and product information were checked on 24 September 2026. See each developer's page for current availability and system requirements.