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
duo, duet, dueto [S], duetto [I], duett [G]—a work for two instruments; the ensemble itself
lullaby, cradle song, berceuse [F]—A lullaby is a soothing song, usually sung to children before they go to sleep. The idea is that the song sung by a familiar and beautiful voice will lull the child to sleep. Lullabies can be found in every human culture, often very ancient. Lullabies written by established classical composers are often given the form-name berceuse, which is French for lullaby, or cradle song. wiki
sonata [I], sonate [pl], suonato—Originally, "sounded" rather than "sung" (sonar vs. cantar), i.e. instrumental music. According to historical period, sonata began to imply a formal plan of movements as well as the structure within a single movement, e.g. "sonata form" and applies to instrumental sonatas, string quartets, symphonies, etc., all examples of the sonata principle. In general usage as a specific work title (e.g. violin sonata), it designates a multi-movement piece for solo or duo instruments with one of the instruments enjoying a feature role. wiki