Answer:
DEFINITION
From c1500 to the mid-1700s (Renaissance and Baroque eras), all music was classified by its social function as being either (1) church music, (2) theater music, or (3) chamber music--a term which included all secular music that was performed in private household--whether vocal or instrumental, solo or ensemble, or even orchestral because at that time orchestras were rather small.
As orchestras grew significantly in size starting in the later 1700s, the term chamber music took on its present definition as music written for and performed by a small instrumental ensemble with one player on each part. Since the interplay of parts is considered an essential element of chamber music, music for a solo performer with or without accompaniment is usually excluded from this definition
