chamber music, Kammermusik [G], musique de chambre [F], musica da camera [I], musica cameralis [L]—"Classical Music" for a small ensemble, generally 8 or fewer players with a canonical emphasis on 3-6 players. explore
fugue, fuga, fuge [G], fuguette, fugen [G,pl]—a contrapuntal procedure (form) involving a musical subject (theme) that is successively imitated by multiple overlapping voices. There is a vast canon of rules (concepts) for creating elaborate and diverse fugues with an infinite variety of character based on fairly specific parameters. Fugues (or partial fugato) are found throughout classical music from the late Renaissance to the present.
nocturne [F], notturno [I], nocturno, Nachtstück [G]—Night music. A romantic character piece depicting moods of the evening or night: quiet, reflective, perhaps romance and melancholy or even restlessness and fantasy. The most famous nocturnes come originally from the piano literature, e.g. John Field and Chopin, et. al.
postlude, postludio, postludium, Nachspiel [G]—a piece (movement) played after a typically larger work; opposite of prelude
prelude, prélude, präludium [G], präludien [G, pl], praeludium, preludio—a movement preceding another almost by way of introduction: to let listeners and players acclimate, often to prepare for greater demands ahead
quartet, quatuor [F], quartett [G], quartetto [I], cuarteto [S]—ensemble or work for four players the most important examples being the string quartet and the piano quartet
scherzo—lively, brisk, typically in a triple meter; usually a three-part form with central, contrasting trio
string quartet, Streichquartett [G], quatuor à cordes [F], quartetto d'archi [I], quartetto di cordi [I], cuarteto de cuerda [S], vonósnégyes [H]—an ensemble as well as music written for that ensemble comprising 2 violins, viola and cello. This is one of the essential genres / forms / ensembles of chamber music and arguably a critical "core" of "classical" music. Explore the string quartet.