Italy was the nursery not only of opera, oratorio and chamber cantata but of the principal instrumental forms, the concerto and the sonata. It was to Florence and then to Rome that Handel traveled in 1706. A good friend of Bach and Handel, Georg Philipp Telemann was a virtuoso performer on almost every instrument, a poet, musical theorist, mathematician, impresario and amateur botanist. He composed vast quantities of music and is listed in the Guinness Book of World Records as the most prolific composer of all time. Vivaldi began his work at Venice's Ospedale della Pietà as teacher, conductor, and composer in 1704, and soon his instrumental works became famous, especially the concertos as heard at the Pietà's public services performed by its brilliant female orchestra. Spencer Carroll (1991)