What problem does it solve? When composing or arranging a song, grooves often feel stiff, melodies fight the rhythm pattern, and tempo choices get confused with beat feel. This Skill provides a structured decision framework for rhythm and groove as musical material, so every rhythmic choice is deliberate and recorded in the ARR-SPEC. ## Core Features & Use Cases - Tempo vs. beat feel separation: Treats BPM and 8-beat/16-beat subdivision as independent variables, with guidance on meter, weight structure of the bar, and meter changes. - Groove construction: Covers syncopation and anticipation (and their precondition that the beat is established), the three ingredients of groove, onbeat versus offbeat feel, bounce, and shuffle. - Melody-rhythm coordination: Defines the three possible relationships between melody and backbeat, plus repetition, displacement, deformation, and contrast techniques for rhythmic figures. - Use Case: A chorus feels foursquare and the melody clashes with the drum pattern. The Skill walks you through accent placement, backbeat relationship selection, and rhythmic contrast, then records the result in the ARR-SPEC fields meta.tempo, meta.meter, and arrangement.groove.feel. ## Quick Start Ask the agent to define the tempo, beat feel, and groove for your song section and fill in the groove fields of the ARR-SPEC.