For the past 20 years, members of the St. Louis Symphony have participated in a series called Live at the Pulitzer. This year’s eclectic line-up of ensembles begins on Nov. 14 with string players of the SLSO playing daring and experimental works by Sky Macklay, Molly Joyce, Michael Gordon, Leilehua Lanzilotti, and Andy Akiho. Akiho’s piece calls for a marimba to join the strings.