Michael Pettry wasn't sure how he felt when terrorists attacked New York and Washington last Sept. 11. But the 21-year-old aspiring composer knew he had to express himself in some way. "After Sept. 11 I felt like I needed to write something about this," the Shepherd College senior and Charleston native said. After trying unsuccessfully to write lyrics about the event, Pettry had an idea. Why not try a requiem Mass to honor the dead? Pettry said he used original Latin texts for his four-movement requiem, but left out some of the more overt Christian references. "I felt, for the purpose of what I was doing, I didn't want to exclude people," he said. "I felt that this was an opportunity for people of different faiths to come together rather than to look inward." Pettry began the piece in October 2001. Though he originally intended the work for an a cappella choir, Pettry decided to add a string quartet to the arrangement. The complete requiem, featuring strings and 15 singers, will be performed at 8 p.m. Friday at St. Peter's Lutheran Church in Shepherdstown. The performance is free. Pettry said it will be the first public performance of the complete work. Excerpts have been well-received. Pettry wrote an orchestral arrangement of the piece's second movement, which recently won Shepherd College's composer's competition. Eventually, Pettry will orchestrate the entire piece and will publish the work. He said the requiem is an attempt to capture the feelings in the aftermath of the terrorist attacks. "I didn't want to recreate what happened on Sept. 11, but I did want to capture that mood of uncertainty of fear," he said. After a somber and sorrowful beginning, he said, the piece moves through fear and anger before ending on a more hopeful note. Pettry said the four-month writing process helped him come to grips with his own feelings about Sept. 11. To contact staff writer Rusty Marks, use e-mail or call 348-1215.