Using Generative Plugins I - Chance
Although IGME can make use of complex generative music algorithms, it can also do simple note transformations. The activity here is to take the part we prepared previously and apply a simple stochastic algorithm that randomly removes notes present in the input sequence to produce output variations (iterations).
The note properties panel can configure various stochastic properties for each note, including pitch, rhythm and the chance of that note happening. For example a note with only 50% probability has only a 50% chance of appearing in the result output.
Firstly open the note properties panel. The interface has several controls, however we are only going to be using the chance rotary control. To apply this to a note in the input score simply select the note(s) you want and then set their probability by moving the slider in the note properties window. A probability of 100% means that the note is guaranteed to be in the output sequence.
For this activity set each 4th note in the sequence to have a 50% probability of occurring (See below).
You should now be able to press the iterate button (or i key) to toggle a new generation and subsequently hear the output. Watch as the right hand side change tracker adds a new entry for each iteration. Note that the generative toggle button must be enabled for the changes to take place.
Now set each 2nd note in the sequence to have a 25% probability (notes 2,6,10 and 14). See below for examples of music created using this process .
Using Generative Plugins II - Random
We will now use a different generative technique to randomise and modify the pitch of each note. Using the same sequence as before, hit the 'Clear Generative Effects'. In the note properties panel take note of the left hand slider.
Next select a selection of notes (as many as you want) then move the slider in the note properties panel. Set the note range to go between -2 and +2 semitones. When you audition the piece each iteration will vary the range of notes between -2 and +2 producing some interesting variations. Feel free to experiment with different ranges and selections of notes.
You might notice that the results produced using this effect create sequences with lots of accedentials. To fix this we can add a pitch quantiser effect in the plugin-list. Simply hit the "+" button and select "Pitch Quantise" from the available options. Move the controls to select a disered key and/or scale. Now each time you hit iterate the sequence will be quantised.
Examples of random permutations created with IGME