Étude sur les mouvements rotatoires; 24 préludes

Microtonal classical is a stream of Western art music that organizes pitch using intervals smaller than the conventional 12-tone equal temperament. Composers employ alternative equal temperaments (such as 19, 24, 31, or 72 tones per octave), just intonation, and other tuning systems to expand harmony, melody, and timbre beyond the familiar semitone grid. The genre foregrounds novel intervals, complex chordal spectra, continuous pitch (glissandi), and fine-grained intonational nuance. It can sound otherworldly, tense, or delicately shimmering, and often requires specially retuned instruments, extended techniques, or custom-built instruments to realize its pitch language.

A prelude is a short, often improvisatory-sounding instrumental piece that traditionally precedes another work or sets a tonal and expressive atmosphere on its own. Emerging in the early Baroque era from the practice of freely extemporizing before a liturgical or secular performance, the prelude evolved from unmeasured lute and keyboard introductions into highly crafted pieces for organ, harpsichord, and later piano. In the 19th century it became an autonomous character piece (e.g., Chopin’s Op. 28), while in the 20th century composers explored cyclic sets across all keys and a wide range of styles (Debussy, Rachmaninoff, Shostakovich). Despite its brevity and flexibility, the prelude typically establishes a key or mode, a figuration pattern, and a distinct mood, favoring clear tonal focus, continuous flow, and a compelling gesture over strict formal constraints.

Classical music is the notated art-music tradition of Europe and its global descendants, characterized by durable forms, carefully codified harmony and counterpoint, and a literate score-based practice. The term “classical” can refer broadly to the entire Western art-music lineage from the Medieval era to today, not just the Classical period (c. 1750s–1820s). It privileges long-form structures (such as symphonies, sonatas, concertos, masses, and operas), functional or modal harmony, thematic development, and timbral nuance across ensembles ranging from solo instruments to full orchestras and choirs. Across centuries, the style evolved from chant and modal polyphony to tonal harmony, and later to post-tonal idioms, while maintaining a shared emphasis on written notation, performance practice, and craft.