DEMPSEY SINGS Army Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, sings a pair of Irish tunes during the 2015 Tragedy Assistance Program for Survivors gala at the National Building Museum in Washington, D.C., March 18, 2015. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 409365-Y-DLP35-965.jpg Photo Gallery