2.10. TuneTwine: Algorithmic Pitch and Rhythm Generator

2.10.1. Documentation

This tool allows the algorithmic generation of polyphonic and polyrhythmic musical lines. The tool interface permits the creation of Parts A through E. Each Part may consist of up to sixteen pitches and rhythms. Rhythms and pitches are independently generated based on the algorithmic selectors. Pitch sequences can be octave shifted and generated either once or many times. Each Part has an independent BPM tempo and GM MIDI instrument.

The tune sequence of each Texture is composed with a vertical column of pop-up menus. Tunes are configured as a sequence of pitches (where middle-C is C4).

The rhythm sequence of each Texture is composed with a vertical column of pop-up menus. Rhythms are configured as a sequence of pulse triples. A pulse triple, occupying each row of pop-up menus, permits the selection of a divisor (division of the BPM-specified tempo), a multiplier (scalar of the divided pulse), and an accent.

Accent values are notated as dynamic markings (loudness measures): the range (pp, p, mp, mf, f, ff), from soft to loud, is provided. An off symbol (o) designates a rest (measured silence). An on symbol (+) designates a maximum value.

Sequences can employ different algorithmic selectors. Algorithmic selectors may choose values from the specified sequence length based on the specified procedure. Procedures include orderedCyclic (in-sequence loops), orderedOscillate (in sequence back and forth loops), randomChoice (equal-distribution random selection), randomPermutate (random re-orderings of the entire sequence), and randomWalk (random movements in single steps up or down the sequence lengths).

Each Texture may have an independent tempo (as entered in the box labeled "bpm"), and an independent GM MIDI instrument (as entered in the box labeled "inst").

The sequence length (labeled "rhythm length" and/or "tune length") determines how many of the vertical column of pop-up menu items are used and selected. This setting determines which rhythms or pitches are used, regardless of how they are specifically configured.

2.10.2. Interface Components

This tool employs the following interface components: Accent Selector (Section 3.1), Beats Per Minute Input (Section 3.2), Octave Selector (Section 3.5), On/Off Switch (Section 3.7), Output Duration Selector (Section 3.8), Output Format Selector (Section 3.9), Pitch Selector (Section 3.10), Pulse Triple Selector (Section 3.11), and Algorithmic Selector (Section 3.12)