Patterns are the fundamental building blocks of Plethora. Patterns are basically strings of MIDI notes. The Generator module contains eight pattern generators, along with some other routing and processing modules. There can be several types of patterns, each using different methods to generate notes. Each pattern has a number of parameters that govern what comes out. The helix module generates repeating random patterns of any length up to 127 steps. Double click on the module to see the following user-settable parameters:
divider (1 - 128) The incoming clock signal (usually 32nd notes) is divided by this value to create longer intervals (pattern steps). For example, if the divider is 2, the pattern will be based on 16th notes. Powers of 2 will result in the conventional note lengths. Other values will produce odd results.
length (0 - 127) This is the length of the pattern in steps as determined by the divider. Patterns will repeat when the number of steps reaches the length. Steps include rests as well as actual notes. If a length of 0 is entered, the pattern will be a non-repeating random stream.
density (0-1) This is the probability that each step will contain a note. For example, if the density is .6, then 60% of the steps will have notes, other steps will be empty rests. Density less than 1 allows for rhythmically interesting or syncopated patterns. Like the note values, the rhythm is also a repeating random pattern (using the same length).
low note (12 - 127) Notes in the pattern are randomly chosen as values between the low note and high note.
high note (12 - 127) If the high note is lower than the low note, their roles will be reversed.
skew (-9 - 9) This allows for a note pattern that is weighted towards the low or high note, rather than being uniformly distributed. For example, a skew of -1 is slightly more likely to produce lower notes, whereas a skew of 9 is heavily weighted towards the high end of the note range.
velocity (0 - 127) This is the base velocity of the generated notes.
vel var (0 - 100) Velocity variation provides some randomness to the generated velocity values. It is calculated as a percent of the base velocity, and varies in both directions. Subtle values can provide a more human or organic feel, more extreme values introduce unpredictability.
gate (ms) (1 - 1000) Gate time in milliseconds is the time between the note on and note off for each generated note. Coordinate this with the envelope settings on your synth or sound module. You might not hear the notes if the gate is too short. If you want gate times longer than 1 second, you can customize the range of this parameter. If you have too many notes with long gate times, you might exceed the polyphony of your sound module, resulting in dropped notes.
note seed (1 - 1000) This number is the genesis of the random pattern for notes. A given seed will always produce the same "random" pattern. This allows for repeatability and predictability. If you want a different pattern (but with the same parameters), change the seed. Yes, this means that patterns are actually pseudorandom, unless the length is 0.
rhythm seed (1 - 1000) The rhythm pattern uses a separate random number generator from the note pattern, thus has it's own seed.
The vector module is another pattern generator, but it is not random. The note pattern is deterministic, based on a triangle waveform. It can be used for creating up, down, or up and down patterns of notes. It has most of the same parameters as the helix module, except that it does not have skew, but has two added parameters, cycle and phase.
cycle (1 - 16) This is the number of steps in the triangle waveform (i.e. the length of the wave).
phase (0 - 100) The pattern can start at any point along the wave. The default is 50, which is the lowest point. So, to create a pattern that goes only down, choose a phase of 0, a cycle of 16, and a length of 8 or less. Experiment with different combinations of length, cycle, and phase to get varying pattern shapes.
