The Seattle Symphony Orchestra is saying goodbye this season to its longtime music director, Gerard Schwarz, with 18 newly commissioned works; the first is this Wednesday, Sept. 8. Maestro Schwarz will conduct the world premiere of Augusta Read Thomas's "Of Paradise and Light" for string orchestra, a four-and-a-half minute piece in the mode of Barber's "Adagio for Strings."

The symphony has commissioned 18 new works by leading American composers, with all premieres to be conducted by Schwarz in the course of the 2010-11 season. Among the composers, besides Schwarz himself, are Gunther Schuller, Aaron Jay Kernis, Samuel Jones, Bright Sheng, Philip Glass, Ellen Twaffe Zwilich, and Daniel Brewbaker.

For the Wednesday concert, the young German violinist Augustin Hadelich, who won the prestigious Avery Fisher Grant last year, joins the ensemble to perform excerpts from Beethoven's "The Creatures of Prometheus" as well as Beethoven's Violin Concerto in D major. The evening at Benaroya Hall begins with a wine tasting at 6:30; wines at $5 a glass. The music starts at 7:30; there is no intermission. Tickets ($9 to $69) online and by phone (206-215-4747).