I recall that Charles Rosen wrote somewhere that one of the reasons the string quartet took off in the classical period was that it allowed the playing of all the notes in a dominant seventh chord without double stops. Although this was probably a better explanation for the relative paucity of string trios in the output of Mozart (1) and Beethoven (0). The establishment of four parts as the "standard" scoring for vocal ensembles can be traced back to the 15th century.
On the other hand the second and more famous dining (and conversation) club founded by Dr Johnson had originally 9 members, and gradually grew from that to dozens. Although many including Johnson may have not been entirely happy with the expansion.
On the other hand the second and more famous dining (and conversation) club founded by Dr Johnson had originally 9 members, and gradually grew from that to dozens. Although many including Johnson may have not been entirely happy with the expansion.