Its success led to an invitation in 1600 for Peri and Rinuccini to write an opera, _Euridice_, for the marriage festivities of Henry IV of France and Marie de’ Medici. Several noblemen, probably members of the “Camerata,” took part in the first performance; one played the harpsichord, and three others played on the chitarrone (a large guitar), a viol da gamba, and a theorbo (double lute). The orchestra was completed by three flutes. This orchestral score was notated in a sort of musical shorthand called figured bass which shows the chords to be used as accompaniment to a melody by means of a bass note with a figure above it. Peri and his colleagues seem to have been the first to use this, but it was adopted by all composers into the 18th century, including Bach and Handel. It was called _basso continuo_ or figured bass or thorough-bass. Caccini also wrote an opera which he called _Euridice_, but it was in the style of a pastoral ballet with songs, dances, and recitatives. This work was probably the result of his having helped Peri in working out his ideas at the meetings of the “Camerata.” This same year, 1600, which finished the 16th century, saw the presentation of Emilio del Cavalieri’s mystery play, or oratorio, _La Rappresentazióne di ‘Anima e di Córpo_ (Representation of the spirit and body), for which Laura Giudiccioni wrote the text. This oratorio, with very elaborate decorations, was sung and danced in the oratory of a church. It must have been very like the operas except that it was based on a religious idea, and was performed in a church, while the opera by Peri was performed at the Pitti Palace and was from Greek mythology. The orchestra was composed of a double lyre, a harpsichord, a double guitar, and a theorbo or double lute. BAIF’S CLUB IN FRANCE While the Italians were trying to find the old Greek and Latin methods of combining drama and music, there was a movement in France to write poetry in classical verse. Following Ronsard’s example, Baif influenced the composers to write music that should express the feeling of poetry, and also imitate its rhythm. They also tried writing madrigals arranged for a single voice with accompanying instrument, or group of instruments. While the Italians invented the recitative, the French developed a rich fluent rhythmic song form, _musique mesurée à l’antique_, or, music in the ancient metre. Baif formed a club or an Academy of poets and musicians much like Bardi’s “Camerata” in Florence. They worked hard to perfect mensural or measured music, and opened the way for the use of measures and bars, which in the 16th century were unknown. We are so accustomed to music divided into measures by means of bars, that it is hard to realize what a great step forward was made by Baif’s Academy. They were struggling to get rid of the plainchant which lacked rhythm as we know it, and which for centuries had used “perfect” or “imperfect” time.