Giovanni Battista was one of the founders of the "Sovvegno dei musicisti di Santa Cecilia", an association of musicians. 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. The Luxembourg scholar Walter Kolneder has discerned the influence of Legrenzi's style in Vivaldi's early liturgical work "Laetatus sum" (RV Anh 31), written in 1691 at the age of thirteen. 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 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. 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". ("" is Italian for "red", and would have referred to the color of his hair, a family trait.) Not long after his ordination, in 1704, he was given a dispensation from celebrating Mass most likely because of his ill health. Vivaldi said Mass as a priest only a few times, and appeared to have withdrawn from liturgical duties, though he remained a member of the priesthood. It is thought that this is also due to his habit of composing while performing mass. He seems to have remained committed to Catholicism, since the entry in the Vienna death records for him reads, "Antonio Vivaldi, Secular Priest". It is thought that he remained a devout Catholic, indeed, in 1792, the Protestant composer Ernst Ludwig Gerber, wrote of the aged Vivaldi that "the rosary never left his hand except when he picked up the pen to write an opera". In September 1703, Vivaldi became "maestro di violino" (master of violin) at an orphanage called the Pio Ospedale della Pietà (Devout Hospital of Mercy) in Venice.