The Calder Quartet saved the day Nov. 4 by stepping in at last minute to play for the Mill Valley Chamber Music Society’s second concert of this season. Originally set to appear was the Prague-based Prazak Quartet which cancelled due to an ill violinist. The Calder Quartet had performed the previous night in Berkeley. In the East Bay concert substantial works were programmed, including Bartok’s 1934 Fifth Quartet, Adés’ The Four Quarters and three Conlon Nancarrow pieces. With such a daunting program Saturday night, one would predict the Quartet to be exhausted on Sunday.