Theodor W. Adorno (alias: Theodor Adorno-Wiesengrund) was born as Theodor Ludwig Wiesengrund in Frankfurt am Main on September 11, 1903, the only child of Oscar Alexander Wiesengrund (1870–1946) and Maria Calvelli-Adorno della Piana (1865–1952). His mother, a devout Catholic from Corsica, was once a professional singer, while his father, an assimilated Jew who had converted to Protestantism, ran a successful wine-export business. Proud of her origins, Maria wanted her son's paternal surname to be supplemented by the addition of her own name, Adorno. Thus his earliest publications carried the name Theodor Wiesengrund-Adorno; upon his application for US citizenship, his name was modified to Theodor W. Adorno.