The thread of development of the Western European musical tradition, which still informs the greatest bulk of music in the Western world, is long and complex.

As was suggested in the discussion regarding patterns, one principle within this tradition has been the desire to control sonic materials. This control is often associated with the "vision" of the composer, that which he or she is attempting to express.

In achieving control over the sonic materials, the traditional composer has strived for establishing a balance among factors of unity and variety, with a tendency to favor factors of unity. In other words, the sonic elements are thought to need coherence, which is mostly achieved by various forms of repetition and proximity of pitches and timbres. Without sufficient unity, a musical work will "fall apart," sound disjointed or incoherent. Too great unity, however, tends to bore us. So some elements of variety are needed to provide excitement.

The organizing system of tonality, described elsewhere, has been the single most significant development of traditional Western European music within the past 400 years. It is a system which has built in to it the essential tools for creating the desired balance of unity and variety. Its employment follows the underlying organizing principle of telling a story, or perhaps more properly, taking one on a sonic journey, with a beginning, middle, and end.

The traditional path is generally conservative, relying on assimilation and appropriation of past techniques, with incremental twists and turns as original minds explore limited new territories. When the explorations range too far from prior practices, tradition is broken and experimentation begins.