earthquake on the day Vivaldi was born, and this rumor may originate from an earthquake that struck Venice on April 17, 1688. The ceremonies which had been omitted were supplied two months later. Vivaldi had five known siblings: Bonaventura Tomaso, Margarita Gabriela, Cecilia Maria, Francesco Gaetano, and Zanetta Anna. Vivaldi's health was problematic. One of his symptoms, strettezza di petto ("tightness of the chest"), has been interpreted as a form of asthma. This did not prevent him from learning to play the violin, composing, or taking part in musical activities, although it did stop him from playing wind instruments. Youth His father, Giovanni Battista, was a barber before becoming a professional violinist and was one of the founders of the Sovvegno dei musicisti di Santa Cecilia, an association of musicians. He taught Antonio to play the violin and then toured Venice, playing the violin with his young son. Antonio was probably taught at an early age, judging by the extensive musical knowledge he had acquired by the age of 24, when he started working at the Ospedale della Pietà. The president of the Sovvegno was Giovanni Legrenzi, an early Baroque composer and the maestro di cappella at St Mark's Basilica. It is possible that Legrenzi gave the young Antonio his first lessons in composition. Vivaldi's father may have been a composer himself: in 1689, an opera titled La Fedeltà sfortunata was composed by a Giovanni Battista Rossi—the name under which Vivaldi's father had joined the Sovvegno di Santa Cecilia. Vivaldi's early liturgical work Laetatus sum (RV Anh 31) was written in 1691 at the age of thirteen. In 1693, at the age of fifteen, he began studying to become a priest. He was ordained in 1703, aged 25, and was soon nicknamed il Prete Rosso, "The Red Priest" (Rosso is Italian for "red" and would have referred to the color of his hair, a family trait.). Career Ospedale della Pietà While Vivaldi is most famous as a composer, he was regarded as an exceptional technical violinist as well. The German architect Johann Friedrich Armand von Uffenbach referred to Vivaldi as "the famous composer and violinist" and said that "Vivaldi played a solo accompaniment excellently, and at the conclusion he added a free fantasy [an improvised cadenza] which absolutely astounded me, for it is hardly possible that anyone has ever played, or ever will play, in such a fashion." In September