Jean-Baptiste de Lully (28 November 1632 – 22 March 1687) was an Italian-born French composer who spent most of his life working in the court of Louis XIV of France. He is considered the chief master of the French Baroque style. Lully disavowed any Italian influence in French music of the period. He became a French subject in 1661.

Lully, son of a working-class miller, was born in Florence, Italy. Lully had little education, but he learned basic techniques on the guitar, originally taught by a Franciscan friar of Florence. Later in France, he learned how to play the violin, and to dance. In 1646, he was discovered by Roger de Lorraine, the chevalier de Guise, son of Charles, Duke of Guise, and was taken to France, where he entered the services of Mademoiselle de Montpensier (la Grande Mademoiselle) as a scullery-boy and Italian-language teacher. With the help of this princess, his talent increased. He studied the theory of music under Nicolas Métru. It has been said that a scurrilous song on his patroness (the doggerel he set to music refers to a "sigh" she produced while at stool) resulted in his dismissal. It is far more likely that he did not want to moulder out in the provinces with the exiled princess.

He came into Louis XIV's service in late 1652, early 1653 as a dancer. He composed some music for the Ballet de la nuit, which pleased the king immensely. He was appointed as the composer of instrumental music to the king, and placed at the head of the Petits Violons, the kings private violin band. In 1661, the King appointed Lully the Surintendant de la musique de la chambre du roi, which brought the twenty-four violons of the Grand Bande of Les Vingt-quatre Violons du Roi under Lully's command.

Lully composed many ballets for the King during the 1650s and 1660s, in which the King and Lully himself danced. He also had tremendous success composing the music for the comedies of Molière, including Le Mariage forcé (1664), L'Amour médecin (1665), and Le Bourgeois gentilhomme (1670). It was when he met Molière that together they created the comédie-ballet. Louis XIV's interest in ballet waned as he aged, and his dancing ability declined (his last performance was in 1670) and so Lully pursued opera. He bought the privilege for opera from Pierre Perrin and, with the backing of Jean-Baptiste Colbert and the king, created a new privilege which essentially gave Lully complete control of all music performed in France until his death in 1687.

He was known to be a libertine. In 1661, in letters of naturalization and in his marriage contract to Madeleine Lambert, daughter of Lully's friend and fellow musician Michel Lambert, Giovanni Battista Lulli declared himself as "'Jean-Baptiste de Lully, escuyer' son of 'Laurent de Lully, gentilhomme Florentin'". Although his life is full of meteoric heights, his love affairs with men and women also brought him down in scandal several times at the great displeasure of Louis XIV. Despite these scandals, he always managed to get back into the good graces of Louis XIV who found Lully essential for his musical entertainments and who thought of Lully as one of his few true friends.

On 8 January 1687, Lully was conducting a Te Deum in honor of Louis XIV's recent recovery from illness. He was beating time by banging a long staff (a precursor to the bâton) against the floor, as was the common practice at the time, when he struck his toe, creating an abscess. The wound turned gangrenous, but Lully refused to have his toe amputated and the gangrene spread, resulting in his death on 22 March. He left his last opera, Achille et Polyxène, unfinished. All three of his sons -- Louis Lully, Jean-Baptiste Lully fils and Jean-Louis Lully -- also had musical careers at the French court.

Lully's music is from the Middle Baroque period, 1650 to 1700. Typical of Baroque music is the use of the basso continuo as the driving force behind the music. The pitch standard for French Baroque music was about 392 Hz for A above middle C, a whole tone lower than modern practice where A is usually 440 Hz.

Lully's music is known for its power, liveliness in its fast movements and its deep emotional character in its sad movements. Some of his most popular works are his passacaille (passacaglia) and chaconne which are dance movements found in many of his works such as Armide or Phaëton.

The influence of Lully's music produced a radical revolution in the style of the dances of the court itself. Instead of the slow and stately movements which had prevailed until then, he introduced lively ballets of rapid rhythm. Lully also enjoyed the friendship of Molière, with whom he created a new music form, the comédie-ballet which combined theater, comedy, and ballet. He played a crucial role in synthesizing, consolidating and disseminating orchestral organization, scorings, performance practices, and repertory.

The instruments in his music were: five voices of strings such as dessus (a higher voice range than soprano), haute-contre (a type of high tenor voice), taille (baritenor), quinte, basse), divided as follows: one voice of violins, three voices of violas, one voice of cello, and basse de viole (viole, viola da gamba). He also utilized guitar, lute, archlute, theorbo, harpsichord, organ, oboe, bassoon, recorder, flute, brass instruments and various percussion instruments.

He is often credited with introducing new instruments into the orchestra, but this legend needs closer scrutiny. He continued to use recorders in preference to the newer transverse flute, and the "hautbois" he used in his orchestra were transitional instruments, somewhere between shawms and so-called Baroque oboes.

Lully founded French opera (tragédie en musique or tragédie lyrique), having found Italian-style opera inappropriate for the French language. Having found a congenial poet and librettist in Philippe Quinault, Lully composed many operas and other works, which were received enthusiastically. Lully can be considered the founder of French opera, having forsaken the Italian method of dividing musical numbers into separate recitatives and arias, choosing instead to combine the two for dramatic effect. Lully also opted for quicker story development as was more to the taste of the French public.

Lully's music is still played regularly via recordings at the Palace of Versailles during the summertime in the gardens, setting the mood for one's visit.