GUEVARA, LUIS VELEZ DE (1579-1644), Spanish dramatist and novelist, was born at Ecija on the 1st of August 1579. After graduating as a sizar at the university of Osuna in 1596, he joined the household of Rodrigo de Castro, cardinal-archbishop of Seville, and celebrated the marriage of Philip II. in a poem signed "Velez de Santander," a name which he continued to use till some years later. He appears to have served as a soldier in Italy and Algiers, returning to Spain in 1602 when he entered the service of the count de Saldana, and dedicated himself to writing for the stage. He died at Madrid on the 10th of November 1644. He was the author of over four hundred plays, of which the best are _Reinar despues de morir_, _Mas pesa el rey que la sangre_, _La Luna de la Sierra_ and _El Diablo esta en Cantillana_; but he is most widely known as the author of _El Diablo cojuelo_ (1641), a fantastic novel which suggested to Le Sage the idea of his _Diable boiteux_. GUGLIELMI, PIETRO (1727-1804), Italian composer, was born at Massa Carrara in May 1727, and died in Rome on the 19th of November 1804. He received his first musical education from his father, and afterwards studied under Durante at the Conservatorio di Santa Maria di Loreto at Naples. His first operatic work, produced at Turin in 1755, established his reputation, and soon his fame spread beyond the limits of his own country, so that in 1762 he was called to Dresden to conduct the opera there. He remained for some years in Germany, where his works met with much success, but the greatest triumphs were reserved for him in England. He went to London, according to Burney, in 1768, but according to Florimo in 1772, returning to Naples in 1777. He still continued to produce operas at an astounding rate, but was unable to compete successfully with the younger masters of the day. In 1793 he became _maestro di cappella_ at St Peter's, Rome. He was a very prolific composer of Italian comic opera, and there is in most of his scores a vein of humour and natural gaiety not surpassed by Cimarosa himself. In serious opera he was less successful. But here also he shows at least the qualities of a competent musician. Considering the enormous number of his works, his unequal workmanship and the frequent instances of mechanical and slip-shod writing in his music need not surprise us. The following are among the most celebrated of his operas: _I Due Gemelli_, _La Serva inamorata_, _La Pastorella nobile_, _La Bella Peccatrice_, _Rinaldo_, _Artaserse_, _Didone_ and _Enea e Lavinia_. He also wrote oratorios and miscellaneous pieces of orchestral and chamber music. Of his eight sons two at least acquired fame as musicians--Pietro Carlo (1763-1827), a successful imitator of his father's operatic style, and Giacomo, an excellent singer.