Music for Montauk will open its fifth season under the leadership of Lilah Gosman and Milos Repicky with “Endeavor,” a free concert by Sybarite 5, a string quintet, on Saturday afternoon at 4 at the Montauk School.“Endeavor” is a mix of recent commissions and premieres from the composers Jessica Meyer, Brandon Ridenour, Steven Snowden, Mike Block, and Michael Gilbertson, a 2018 Pulitzer Prize finalist. The program will also include compositions by Aleksandra Vrebalov, Pete Seeger, and John Coltrane.Sybarite 5 consists of Sami Merdinian and Sarah Whitney, violins, Angela Pickett, viola, Laura Metcalf, cello, and Louis Levitt, bass. The group’s repertoire ranges from Bowie to Radiohead to Mozart, and its most recent album, “Outliers,” which features all new works by American composers, rapidly rose to number one on the Billboard classical chart.The group has performed across the country, from the Library of Congress and the Schubert Club in St. Paul to the Anchorage Concert Association and the Sun Valley Center for the Arts, as well as concerts in New York City at Carnegie Hall, Lincoln Center, National Sawdust, the Apple Store, and the 92nd Street Y. During its current residency at the Cell theater in Manhattan, Sybarite 5 is experimenting with new sounds and programming innovations.A post-concert party will be held at Gosman’s restaurant in Montauk from 5:30 to 7 p.m. Reception tickets are $35 in advance, $40 at the door, and available at musicformontauk.org.A summer series will run from Aug. 15 through Aug. 24, with outdoor concerts at Third House, special events, and a site-specific performance at the Montauk Lighthouse.Founded as the Montauk Chamber Music Society in 1983 and renamed in 1991, Music for Montauk offers classical music, multimedia performances, dialogues, and educational programs dedicated to bringing a fresh and dynamic approach to classical music throughout the year. M.S.