MIDDLETOWN-The Delaware Valley Chamber Orchestra will perform an afternoon of new music at Orange County Community College in Middletown at 3 p.m. Entitled "Music of Our Time," the program will showcase contemporary classical music, created by living composers. Orchestral works by seven composers are on the program, including vocal and instrumental soloists. The composers are Chris Parker of Port Jervis, Susan Gum of Kingston, David Tcimpdis of Livingston Manor, Kenneth Somerville of Monticello, Joe Hannan of New York City and Callicoon, Ben Barshai of Beach Lake, Pa., and Gladys Smuckler Moskowitz of Woodbourne. The performance at Sunday, Oct. 24, at Orange Hall Theater. Admission is $5 for adults, $3 for senior citizens, $2 for students, and free for students of the college. The Delaware Valley Chamber Orchestra is an outgrowth of the Ill Winds Chamber Ensemble, which was formed in 1975. The general manager of the orchestra is Gloria Krause of Narrowsburg, who also plays bassoon. Ron DeFesi of Florida directs the orchestra. This performance is partially funded by Sullivan County Decentralization, a regrant program of the New York State Council on the Arts and by the Sullivan County Arts & Heritage Grant. The performance is a Lyceum Event presented by the college's department of Cultural Affairs. For more information call 341-4891 or e-mail firstname.lastname@example.org.