RHY.2:4 - Solution
RHY.2:4.1 - Start with the required discrimination
Ask what two possibilities must remain distinguishable. Examples are an entrance after the third rather than fourth attack, an accent produced by pressure rather than a break in contact, and a full rather than partial weight transfer.
Use the smallest material portion that contains the relevant relation. Extend it when the boundary matters: a cyclic pattern needs its return to the next cycle; an entrance may need the preceding cue; a continuous change may need more than its peak.
RHY.2:4.2 - Identify what actually changes
Locate the sound-producing action, movement, contact, load change or other occurrence involved. Say which body, instrument or material changes. If the analysis concerns a perceived grouping or accent, include the responding listener or partner and the task in which that response occurred.
Select suitable units for the question. They may be bounded actions, portions of a continuous trajectory, identifiable positions on that trajectory, or relations among several such contributions. Define a start, completion or threshold only when it serves the question. If more than one boundary is plausible, preserve the alternatives or use an interval.
A detected peak is an observation made under a detection rule. Connect it to the event it is supposed to indicate before using it as a count of performed actions.
RHY.2:4.3 - Preserve the relations that affect the result
Recover order, separation, grouping, recurrence, phase, accent or coupling only where they change the receiving use. State the reference: “after the singer’s pickup,” “within this eight-unit cycle” or “relative to the partner’s perceived arrival” can be more useful than a bare timestamp.
Keep continuous contributions when their course matters between selected positions. A brush can remain in contact while pressure varies; a dancer can continue a weight path while a foot articulates an extra sound. Marking only the accents would erase the relation the practitioner must preserve.
Distinguish an observed relation from a proposed one. A desired coincidence of sound and movement is a performance instruction until an occurrence supports the corresponding observation.
RHY.2:4.4 - Try the selection against the question
Use the selected information to answer the question or reconstruct the intended part of the activity. Then change a feature that the selection omits. Would that change the answer?
If yes, include the missing feature, obtain its observation, or narrow the claim. If no, the omission can be useful simplification. This test applies to the operation and conditions being considered; it does not declare the omitted feature irrelevant to every rhythmic use.
For a numerical analysis, keep the rule that produced the numbers. An onset detector’s threshold, the treatment of a cycle boundary, or the choice of a perceived rather than physical event can alter the result.
RHY.2:4.5 - Hand over a usable account
Show the selected units, their consequential relations and their connection to the activity. Keep enough source material or demonstration for the next user to recover the intended reading. State uncertainty where it changes that user’s action.
Keep observed changes and proposed changes distinguishable in the account. A.22 governs the selected structure of the activity; C.2.1 governs the description of it.
Stop when the account supports the current operation. RHY.5 can develop its representation for repeated use; RHY.7 can compare alternatives. A missing relation may instead call for a focused observation.