'For Four (Caldera)' is a composition in the form of a canon, where four singers are facing the cardinal directions in a valley that was created by a sudden disruption. Each singer slowly rotates while scanning the horizon line, interpreting its contour as a melodic line. 'For Four (Caldera)' is a video installation showing four women standing on a volcanic hollow in the Jemez Mountains of New Mexico, near the site of Los Alamos National Laboratory where the atomic bomb was developed.