The name of Virginia Vagnoli, a renowned Sienese singer who was active for several years at the court of Guidubaldo II della Rovere, Duke of Urbino, is known thanks to research carried out by scholars as well as to some fortunate circumstances. She was the most prominent musician at Guidubaldo II's court at Pesaro, and her name appears in several mid-sixteenth-century documents: Francesco Sansovino's Le cento novelle (second edition, 1562), the title page of Giovanni Maria Rosso's Il primo libro di madrigali a quattro voci, published and dedicated to her by Claudio Merulo; the dedication to Guidubaldo II of the treatise De origine et dignitate musices, by Pietro Caetano, singer at St Mark's; and, above all, the literary works of the poet Lodovico Agostini.