Visitors gather at the Baha'i House of Worship in Wilmette, Illinois, for a special commemorative program held on 29 April 2012, marking the centenary of 'Abdu'l Baha's laying of the building's cornerstone. Three services included prayers read by children in several languages, selections of sacred writings sung by the Temple's choir, and the rare opportunity for visitors to hear a recording of 'Abdu'l-Baha's own voice.