Chamber Orchestra means an Orchestra has less than 50 players. Chamber Orchestras can vary widely in size, and they may have more than 50 players on staff, allowing for substitutions as needed while providing a pool of specialized talent. A harpist, for example, may be necessary in some pieces but not in others. Chamber Orchestras tend to perform smaller, more intimate pieces. Music for Chamber Orchestra can get quite complex, especially when it calls for a large complement of players.