Note: this independently contributed article has not yet been reviewed for accuracy by Karma-Lab.
Revise following summaries to explain how Index group and Drum group interact too
- Plain English summary: The Index Pattern in the Index group and the Cluster Pattern in the Cluster group always work with each other to determine exactly which note pitches from the Note Series to play at every step of a Phase.
- More exact description: The Index group determines which index in the Note Series is the starting point of each Cluster (and how the Cluster is spread out) that is played at each "Rhythm Step" during a Phase. (And the Cluster group determines how many notes to play (the "cluster size") at each Rhythm Step.)
In its simplest form, the index pattern shown in the grid tells the Note Series which index in the playable Phase Area to advance to next after playing the current Cluster. At each Rhythm Step of a Phase:
- The Cluster at the current index of the Note Series is played, and then after that happens the current value in the Index Pattern is applied to specify which index in the Note Series will be the starting point of the next Cluster played in the next Rhythm Step, and so on.
For example, if you see a +2 at the current step of the index pattern, this is not affecting the starting index of the Cluster that is played at this Rhythm Step. (It was the value of the previous step of the index pattern that determined what Cluster notes you are hearing in the current Rhythm Step. So maybe it helps to think of the values you see in the Index Pattern as "lagging behind" what you're actually hearing by one Rhythm Step. Another way to think of it is that step 1 of the Index Pattern controls the Cluster that you hear played in step 2 of the Rhythm Pattern , step 2 of the Index Pattern controls the Cluster that you hear played in step 3 of the Rhythm Pattern, and so on. (What controls the Cluster played in step 1 of the Rhythm Pattern phase is determined by some parameters over in the Phase group.)
- A 0 value in the Index Pattern moves forward by 0 indexes. In other words, the same index used as the starting point of the Cluster in the current Rhythm Step will be used as the starting point of the Cluster in the next Rhythm Step. There is a subtlety here, in that the Cluster played in the current Rhythm Step might have been only one index (one note pitch), but in the next Rhythm Step the Cluster might be several indexes (multiple note pitches) because random pools are very common in Cluster Patterns. The net result is that even though the index has not advanced from the previous Rhythm Step to the current Rhythm Step, you might hear different notes being played (but the bottom note will always be the same in both instances).
- A +1 value in the Index Pattern moves forward (to the right) by 1 index. In other words, the next index in the Note Series will be used as the starting point of the Cluster in the next Rhythm Step. A +2 value moves the Note Series index forward by 2 indexes, a +3 value moves the Note Series forward by 3 indexes, and so on.
- A -1 value in the Index Pattern moves backward (to the left) by 1 index. A -2 value moves the Note Series index backward by 2 indexes, and so on.
Example of how the Index Pattern chooses which index of the Note Series to play
Assume that your GE is set up as follows:
- When you play a CMaj7 input chord, the resulting Note Series is 4 indexes long:
C3 E3 G3 B3
- In the Cluster group, the Cluster Pattern uses a cluster size of 1 for every step in the pattern (meaning only one note is played per Rhythm Step). So the Cluster Pattern looks like:
1 1 1 1 1 1 1 1
- In the Index group, the Index Pattern is 8 steps long, with the following sequence of values:
0 0 +2 +1 -2 +1 0 0
- Remember, as described above in The important basics, some parameters over in the Phase group determine the first index that is used for the first step of the Rhythm Pattern in a Phase, so the Index Pattern values are applied after the first Cluster plays, always "lagging behind the current Rhythm Step" by one step. So let's assume that those other parameters in the Phase group:
- Specify to use index 1 of the Note Series for the first Cluster played in step 1 of the Rhythm Pattern for the Phase. In other words, C3 is the only note played in the first Rhythm Step.
- The defined length of the Phase is such that 8 steps through the Rhythm Pattern matches the Phase length, so the Phase effectively ends after the 8th Rhythm Step.
So in this example, the Index Pattern and Cluster Pattern working together with that "first index" specified in the Phase group would play the following sequence of notes, with (C3) representing that "first index" specified by the parameters in the Phase group:
(C3) C3 C3 G3 B3 E3 G3 G3
To spell the events out one by one:
- Step 1 of the Rhythm Pattern: The Phase group says to play index 1 of the Note Series, and the step 1 of the Cluster Pattern says to play one index, so a single C3 is played. Then step 1 of the Index Pattern is applied, and it says to move 0 indexes forward (to the right) to get ready for the next Rhythm Step.
- Step 2 of the Rhythm Pattern: Step 2 of the Cluster Pattern says to play one index, so a single C3 is played again. Then step 2 of the Index Pattern says to move 0 indexes forward to get ready for the next Rhythm Step.
- Step 3 of the Rhythm Pattern: Step 3 of the Cluster Pattern says to play one index, so a single C3 is played again (the Index Pattern has not yet said to move the Note Series index forward, so we've been staying on C3 this whole time so far). Then step 3 of the Index Pattern says to move forward by +2 indexes (at last!)
- Step 4 of the Rhythm Pattern: Step 4 of the Cluster Pattern says to play one index, so a single G3 is played. Then step 4 of the Index Pattern moves the index forward by +1
- Step 5 of the Rhythm Pattern: Step 5 of the Cluster Pattern says to play one index, so a single B3 is played. Then step 5 of the Index pattern moves the index backward by -2
- Step 6 of the Rhythm Pattern: Step 6 of the Cluster Pattern says to play one index, so a single E3 is played. Then step 6 of the Index Pattern moves the index forward by +1
- Step 7 of the Rhythm Pattern: Step 7 of the Cluster Pattern says to play one index, so a single G3 is played. Then step 7 of the Index Pattern moves the index forward by 0 (no movement)
- Step 8 of the Rhythm Pattern: Step 8 of the Cluster Pattern says to play one index, so a single G3 is played. What happens with the 8th step of 0 in this Index Pattern? What index (note) will be played next in the Note Series now that the Phase is starting over on the next Rhythm Step? Well, two different things could happen depending on whether the Phase is set up to do some type of index restart within the Note Series and whether it is doing some type of pattern restart within the Index Pattern. So there's four possibilities for what will happen, but we'll simplify things and assume that the Phase group is telling the Index Pattern to restart (pattern restart) every time this same Phase restarts. So now there's only two things that might happen:
- If the Phase group specifies to restart the Note Series at its first index, the 8th step of the Index Pattern is just ignored completely and we start over again on index 1 (C3) at the first Rhythm Step of the next Phase.
- If the Phase is not set to do an index restart of any sort, when we loop to the start of the phase again at Rhythm Step 1, we move exactly 0 indexes forward (because the 8th step of the Index Pattern is 0) from where we left off at the end of the previous Phase (index 3 — G3), so the first note played at the start of this new phase is G3 instead of C3 like it was the first time through the Index Pattern. This means that this time through the Phase, the sequence of notes played would be:
G3 G3 G3 C3 E3 B3 C3 C3
How the Random Pools work
Placing more than one value in the same column of the pattern grid creates a Random Pool at that step of the pattern. When a step containing a Random Pool occurs, one of the values from the pool is chosen at random, based on the effects of the Weighting Curve and Weighting Factor parameters.
- Slanting the curve towards the top (a positive Factor that shows more orange color than green color in the graph) results in the higher values from the pool (the values closer to the top of the pattern grid) being chosen more often.
- Slanting the curve towards the bottom (a negative Factor that shows more green color than orange color) results in the lower values from the pool (the ones closer to the bottom of the grid) being chosen more often.
- Several different curves are provided to influence the choices in different ways. Setting the curve in the center (a Factor of 0) produces a straight diagonal line and an equal chance of any of the values from the pool being chosen.
- A Factor of 99 results in a solid orange color, which means the highest value in the pool is always chosen.
- A Factor of -99 results in a solid green color, which means two different possiblities depending on whether the curve is S-shaped or not (Exp-S and Log-S)
- For regular curves, the lowest value in the pool is always chosen
- For S-shaped curves, either the highest or lowest value in the pool is chosen (50-50 chance of either).
- A simple way to remember the meaning of the color codes in the visual graph is that orange is a "warm" color and green is a "cool" color, and warm air always sits above cold air. Therefore more orange always means higher pool values are favored, while more green means lower pool values are favored.