The University of Virginia’s University Singers will be performing for audiences in England, Czech Republic, Poland and Austria. The ensemble’s first international tour in several decades is set for May 19 to 28. The singers, led by faculty conductor Michael Slon, will perform works by Whitacre, Part, Lukaszewski, Dvorak, Bruckner, Finzi and Biebl. Some American folk songs and spirituals also will be on the program.