The Park Avenue Armory is currently hosting an impressive indoor installation: A series of 11 massive, hollow concrete towers set in a semi-circle. Together they comprise artist’s Taryn Simon’s Occupation Of Loss, a meditation on grief and how we deal with it. Each silo-like structure is 48 feet high, and serves as a setting for live a performance by a professional mourner (one of a group of 30 altogether, hailing from Greece, Burkina Faso, Russia, Venezuela, Albania, Kyrgyzstan, Armenia, and elsewhere) who sings and chants and performs other rituals while sitting inside. A viewer can enter the tower to observe the performer up close and personal. Between performances, visitors can go in to test out their own voices if they care to. The structures were built in collaboration with OMA, the design firm headed by international starchitect Rem Koolhaas. Occupation Of Loss is at the Armory until September 25.