Commando: Known for his experience in Somalia, Matt Eversmann takes on a new mission: music. In a tailored suit and silk tie, he teaches the finer points of leadership to executives in corporate America. In Army camouflage, he molds young adults at the Johns Hopkins University into future combat leaders. Master Sgt. Matt Eversmann excelled in some of the military's most grueling schools, and he led a team of commandos in the bloody battle that inspired the book and movie Black Hawk Down. A colleague described him as an "Army rock star." So with two years remaining in his 20-year...