TidalCycles patterning stacks four levels: sequence, symmetry, deviation, and composition/interference

Magnusson and McLean describe TidalCycles as a multilayered view of pattern making, each layer building on those beneath. The base is sequence — a linear, potentially polyphonic or polymetric list of events. The second is symmetry — time operations like reversal and rhythmic rotation, or note-value operations like inversion. The third is deviation — imperfections, glitches, and confounded expectations introduced via randomness (sometimes, rarely, often). The fourth is composition, culminating in interference, where joining patterns yields features present in neither. As you climb these layers, code becomes more important to the creative process and ‘more like physical material’, with the performer reacting to emergent results rather than transcribing a pre-planned idea. The hierarchy maps onto stages of live-coding performance maturity.

Examples

Sequence: s “bd sn hh”. Symmetry: rev $ s “bd sn hh”. Deviation: sometimes rev $ s “bd sn hh”. Composition/interference: weave 16 (pan sine1) [s “bd sn”, s “hh cp”].

Assessment

Name the four levels of patterning and give a one-line TidalCycles example for each; identify which level involves features not predictable from the inputs.