Calling a form is not choosing a mood. It is issuing an instruction, and the instruction reaches every section at once: the meter everyone counts in, the bar grid the number will run through, the harmony it will move over, and the exact pattern in every strumming hand. Nobody negotiates afterwards. That chain is the thing this site exists to describe, and it is why the forms have a page of their own above the pattern engine rather than inside it.
THE BAR GRIDS BELOW ARE SCHEMATIC and this page says so rather than pretending otherwise. A son as played runs coplas and estribillos as long as the dancing lasts; what is stable is the SHAPE — an instrumental call, a sung passage, a refrain answering it — and that is what these counts describe. The bars-per-pass column is arithmetic over the grid, not a claim about any recording.
THE HARMONY IS DERIVED, NOT TYPED. Each form declares which diatonic degrees it habitually uses; the chord names come from the shared key tables, so the same declaration is correct in all twelve keys. Functions are named in words — tonic, subdominant, dominant, submediant — and never written as a run of digits. That notation belongs to a different sister site, and borrowing it would be borrowing somebody else’s subject.
ONE FORM CARRIES NO CELL, on purpose. Huapango runs the same grid the son does; what makes it itself is the falsetto in the sung line and the syncopation across that grid, not a different pattern in the hand. Declaring a fifth cell to fill the column would be inventing data, so the column says so instead, and scripts/validate-forms.js pins that exactly one form is uncelled.