Symmetry is a Tango Topics definition, and musical construct that uses Alternation as a way to express our ideas in a structured and methodical manner. That structured manner shows the casual observer that we’re hearing the music and executing the structure of the music.
In its simplest form Tango Symmetry uses ‘pairs’ of vocabulary choices, either within the pause structure (meaning between two musical pauses) or as a pair of pauses to create the idea of structure in the music. Like for instance starting out with a Parallel System walk on 2 tracks, and then continuing on after the next Musical Pause up to the next one with that same Parallel System walk, and then at the next Musical Pause engaging Alternation and picking another piece of vocabulary and holding it for another par of pauses. That’s Symmetry as a tool and practice. If you are curious, this idea is fully fleshed out in sections 3 and 4 of the Musical Interpretation series.