Here’s a novelty few can have seen coming: The Triumph of the Octagon, by Philip Glass, dashed off for the Chicago Symphony Orchestra under Riccardo Muti, who this season assumes the title of music director emeritus for life. The association between the maestro and composer began in February 2022, when Muti, then 80, and his Chicago ensemble took up Glass’s Symphony No. 11. The lush, adventurous score had premiered at Carnegie Hall on January 31, 2017, Glass’s 80th birthday, when it was performed by his longtime champions Dennis Russell Davies and the Bruckner Orchester Linz. Muti and the Chicago players, on the other hand, were dipping their collective toe into the Sea of Glass for the very first time. Now, The Triumph of the Octagon heads up an Italian-themed program to be heard on the musicians’ home stage, in the Windy City. —Matthew Gurewitsch