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
consort—A 17th century English word for chamber ensembles including "whole" consort for instruments of the same family (e.g. viol consort) and "broken" consort for a diversity of instruments. wiki
piano quintet—ensemble (work) for string quartet plus piano. One of the most grand chamber music forms. For an extra rich sound, some piano quintets omit the 2nd violin and add a bass comprising the complete four-part string section of the orchestra.
quintet, quintette [F], quintett [G], quintetto [I]—an ensemble / work for 5 players, the typical examples being string quintet (with second viola or cello), piano quintet or woodwind quintet
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.