Musical flow is the succession of sounds (and silences) that spans the duration of a piece. It’s the way a piece unfolds for the listener; its rhythmic and melodic dance; its storyline. A piece’s musical flow cannot be reduced to a simple formula, diagram, or analytical mapping. Flow is a complex and mysterious quality, more alchemical than scientific. It is a very important part of what makes a piece work (or not), so composers owe it to themselves and their listeners to pay attention to flow, to find their personal flow and develop it.
The first thing to consider in musical flow is density: the number of musical events (notes, beats, impulses, hits) that occur in a given period of time. Unchanging density tends sooner or later to stasis. For example, if an audible percussive event occurs on every 16th of every beat, after a while the groove will become static, predictable, dull.
Changing density makes passages dynamic. If some 16ths are skipped, others accented or played very softly, others subdivided into 32nds or even 64ths (ie, a roll), the groove becomes less predictable, more engaging. Unless the goal is to induce a trance state via rote repetition, variety of density is a key factor in keeping your listeners tuned in.
Another key determinant of flow is the rate at which new material is served up. Just like unchanging density, unchanging material tends to stasis. No matter how gorgeous a beat loop might be, if it repeats long enough without any dropouts or additions, it begins to sound mechanical and dead. Build-ups are compelling because of the gradual accretion of new material, layer by layer: snare, plus hi-hat, plus kick, plus bass, plus effects, and so on. A skilful composer knows exactly when new material is needed to keep listeners creatively imbalanced; unsure of what’s coming next; interested.
Forward momentum is another key factor in musical flow, especially for high-energy genres such as dance or drum ’n’ bass. The beat must propel listeners forward in time, keep them moving internally and, in the case of dance genres, externally. Ambient, on the other hand, often works with zero or even backward momentum, in which the listener is encouraged to slow down, lose themself in contemplation, listen to the moment or perceive echoes from earlier passages in the piece.
On the global level (that of the entire piece), flow manifests through the interplay of longer sections (typically between four and 32 bars). In electronica, these sections generally include: intros and closings, build-ups, mains, dropouts, bridges and breaks. The way that a piece’s sections arise, develop and transition among each other gives way to a kind of ‘plot line’. The dramatic contour of a well-plotted piece generates a suspenseful and riveting sonic story, thus keeping listeners engaged.
No one can tell you exactly how to work the flow of your pieces. Your personal musical flow is as idiosyncratic and unique as your personal sense of melody, rhythm, timbre. Become aware of your unique flow, develop it, stay true to it – in the end, your music will love you for it!