The discrete, riff-based composition of metal songs challenges models that explain goal- directedness through continuous progression of musical materials. This paper argues that local and global musical events are directed by presentational and fluid characteristic tendencies -- which are organized along a syntactical hierarchy whereby notes are grouped into riffs, into riff modules, into sections, into supersections, into whole-song forms.

Presentational supersections are usually vocal-dominated, may contain numerous sections directed toward one goal (typically a verse-chorus cycle; Nobile 2020) and sound precomposed, fostering repetition throughout a composition. They can either present rotations of the same material or introduce new material (Hepokoski and Darcy 2006, Hudson 2021). Fluid supersections are primarily instrumental-dominated, contain any number of goals, sound extemporaneous and resist repetition. While form in metal songs strongly parallels that of other rock music, genre-specific functions and the discontinuous nature of riffs transmogrify rock prototypes according to metal's social practices and instrumentation. Characteristic tendencies explain the architectonic division of form through the inherent qualities of supersections, but also the various ways in which the constituent elements relate. Thus, this model reconsiders conventional approaches and prioritizes in-the-moment experience as a generator of organic unity.