Orchestral Works Vol. 5: Metastaseis; Pithoprakta; ST/48; Achorripsis; Syrmos; Hiketides

Stochastic music is a 20th‑century avant‑garde approach in which musical parameters are governed by probability theory and random processes rather than fixed, note‑by‑note determination. Instead of traditional melody and harmony, composers shape "sound masses" by controlling statistical features like density, event rate, pitch distributions, durations, and dynamics. Typical tools include Gaussian, Poisson, and Markov processes, which create evolving textures, swarms, and clouds of sound—often realized in both orchestral and electroacoustic settings. The term is most closely associated with Iannis Xenakis, who formalized the method and demonstrated it in landmark works and writings, but it has deeply influenced computer music, experimental electronic practices, and later microsound/granular approaches.

Orchestral music refers to compositions written for an orchestra—a large ensemble typically built around a string section (violins, violas, cellos, double basses), complemented by woodwinds, brass, percussion, and often harp, keyboard, or other auxiliary instruments. A conductor coordinates the ensemble, shaping balance, phrasing, and expression. The style emphasizes coloristic timbre combinations, dynamic range from the softest pianissimo to explosive tuttis, and textures that can shift seamlessly between transparent chamber-like writing and monumental masses of sound. Orchestral writing underpins concert genres such as symphonies, overtures, and tone poems, as well as opera, ballet, and modern film and game scores. While orchestral writing evolved across centuries, its core craft centers on melody, counterpoint, harmony, register, and orchestration—the art of assigning musical ideas to instruments to achieve clarity, contrast, and narrative impact.

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.