Random rhythm generator

Figure 2.23: Random rhythm generator toolbar

This dialog generates rhythms from some kind of statistical specification. You define probabilities for timing, velocity and note-length and from these the rhythm is generated.

With the three sliders you specify the meter and (with # Bars) how many probabilities you want to define. Next, you can add or remove instruments to the listbox. Then you specify the probabilities for rhythm, velocity and length for each instrument.

Probabilities are set with the mouse where

• left button - draw some kind of curve
• right button - clear values to zero
• + shift - adjust all values simultaneously
• + ctrl - adjust exactly one value

In the rhythm field you specify the probabilities for every time position. A high value means a high probability that the instrument is played definitely at that time. A low value means, that the instrument may be played at that time. By adjusting high values only, you can specify a definite rhythm without any randomization.

The velocity (and length) values are looked up by the generator, whenever it decides to play a beat. It chooses one value from 1..127 (x-axis, 1..8 for length) where positions with high probabilities are chosen more often.

If the chosen length is greater than 1 step, there are no more events generated until the note quits, even if there are high probabilities in the rhythm field. You can abuse this, to make sure that there are not too many events generated (example: you have rhythm probabilities at step 4 and 5, but you want exactly one beat to be played at either of these. Specifying a length of 2 will do this, if step 4 is chosen, there cannot be an event on step 5). The length may also be used for rhythms where you want to have random intervals between the beats but you are not interested in the absolute timing positions of the beats. Look at the cowbell definition in the rrg1.rhy example for this.

We had the best results with the following: define every instrument twice. In the first definition, select high probabilities on a few timing positions together with high velocities, this makes the base groove - it is loud and does not change very much. In the second definition, have little probabilities on many timing positions with a low velocity, this makes randomized background fills, which make the whole thing more interesting and that do not override the base groove because of the low velocity.

Aside from drums there are some special 'Instruments' you can select:

• Controller - opens another dialog to select a controller. Randomizing works the same like with drum keys except that instead of velocity the controller value is generated. With this, you may generate for example random panpot events that move the sound between left and right speaker or, in conjunction with the Parts Menu, you can generate many different randomized sound effects.
• Pianowin all - places the events currently selected in the piano window. You could eg select a chord an then replicate it on random timing positions.
• Pianowin one - like pianowin all, but on every timing position there is chosen one of all the selected events.

The events selected in pianowin are copied to an internal rhythm buffer, so you may define multiple rhythms with different pianowin selections.

To generate, you select some bars on one track in the trackwin and press the gen button.

Instruments without randomizing
Instrument Groups