The Guggenheim Museum's walls are bare at the moment to make room for a piece by conceptual artist Tino Sehgal called "This Progress."
Last year classical musician Meredeth Rouse signed up for the U.S. Army Band. Alongside soldiers nearly half her age, she had to get comfortable with rifles, hand grenades, and chemical warfare. In the Army, even an oboist has to get through boot camp.
Susan Sontag and others talk about how artists help us to make sense of war -- from photography and books to poetry and film.