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
ma—but, however
serenade, serenada, serenata [I], sérénade [F]—A suite of movements like a divertimento with similar connotations of lightheartedness, pleasure and relative calm with an emphasis on lyricism and often beginning with a march. Historically evokes the evening, outdoors, an honorific or amorous tribute, especially from a suitor to a lover in a window or balcony. The word serenade has its Latin origins the Latin word for "calm" or serene. wiki
sonata, sonate, suonato—a complicated term. Originally, "sounded" rather than "sung" (sonar vs. cantar), e.g. 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. In general usage as a work title, it designates a multi-movement piece for solo or duo instruments with one of the instruments enjoying a feature role.
troppo [I], non troppo, trop [F]—too, too much. non troppo means "not too much". e.g. "Allegro ma non troppo" means fast, but not too much