Five leaders of the Czech independent cultural group the Jazz Section went on trial Tuesday, charged with conducting illegal commercial activities. If convicted, the defendants--Karel Srp, Vladimir Kouril, Josef Skalnik, Tomas Krivanek, and Cestmir Hunat--face up to eight years in jail. Their appearance in a Prague court was wildly applauded and cheered by about 100 supporters packing the corridor outside. Milos Drda, 73, who acted as the group's treasurer, and his son, Vlastimil, have been excluded from the proceedings for health reasons and will be tried later. Also on Tuesday, the U.S. State Department urged Czechoslovakia to stop persecuting the Jazz Section, calling it a "significant voice for independent cultural expression."