As physical players of our instruments, we need a practice of cleansing the fibers of our muscles as we play. So play becomes the fiber to cleanse and relax the "fibers" of our muscles.
Chamber music, read at relaxed parties, with lots of yummy hors-d'oeuvre and good wine, becomes a necessary part of staying fresh in our playing.
We need play, in the sophisticated setting of Mozart's brilliance, to ripen our musical souls as expressed through our bodies, and for those corporeal souls to flourish.
Great chamber music offers an individuality rarely present in the orchestra, except in solo parts. But even in orchestral solo parts, the player is subject to so many exterior demands, such as the thoughts of the conductor and acoustics, not to mention the sheer number of other "opinions" extant. So chamber music is "soloing" at home with good friends. Could there be any better way of learning trust and physical poise in an intimate setting?
So, back to fiber. We all need it. Fiber for the body, the soul and the mind.