An Italian composer; born at S. Vito degli Sclavi, now called S. Vito dei Normanni, near Brindisi. His musical talent was discovered by the Dominicans, who taught him for a while, then persuaded his mother to allow him to continue at Naples. He entered the Conservatory della Pieta dei Turchini at the age of nine, remaining there until 1715. Here he studied under Provenzale and Nicola Fago il Tarentino. Although influenced by Pitoni and Scarlatti he could hardly have studied with them as he was too poor to go to Rome to be under the former and when Scarlatti taught in Naples it was at Poveri di Gesu Cristo. His first composition was a sacred drama on the subject of Santa Chiara, entitled L'Infedelta abbattuta. This was performed by the students of the Conservatory during the carnival of 1712. His first secular opera was Pisistrato, in 1714, and was very successful. The next year he was made second master at the Conservatory and organist of the cathedral, following which he became Court organist. He also became chapelmaster at the Church of S. Maria della Solitaria, which belonged to a convent of Spanish nuns. In 1718 he produced Sofonisba, which is supposed by many to have been his first opera, probably because it established his reputation as a writer for the stage. His .next work of note was the composition of recitatives and comic scenes for Gasparini's Bajazette, a comic opera, and this started Leo upon his brilliant career as a composer of comic opera. Upon the death of Scarlatti, he became first organist of the Royal Chapel, and his fame began to become widespread. In 1732 he succeeded Vinci as Provice-maestro of the Royal Chapel. The same year he produced his two celebrated oratorios, La Morte di Abele and Santa Elena al Calvario. Demofoonte appeared in 1735 and was probably the most successful of all his operas. His operas were produced in many Italian cities and he often went to superintend their performance, being absent from Naples for months at a time. In 1741 he succeeded Nicola Fago as first master at the Pieta dei Turchini and thereafter seems to have remained in Naples until his death. He died while seated at his harpsichord, from a stroke of apoplexy. The bulk of Leo's work has never been published. Of his sacred compositions, which include oratorios, masses, motets, hymns, magnificats, etc., the best known is a miserere for eight-part choir. His fame rests chiefly on his sacred music and his comic operas. He was an indefatigable worker, composing at night when other duties claimed him through the day. In person he was handsome and dignified. His figure was of middle height and his manners were pleasing. He was well loved by his pupils, among whom were many distinguished musicians.