The word baroque was a Portuguese term for a pearl (barocco) with an irregular shape. Cognates for the term in other Romance languages include: barroco in Portuguese, barrueco in Spanish, and barocco in Italian. It was used in French to describe pearls in a 1531 inventory of Charles V's treasures.
In the 18th century, the term was usually used to describe music. In an anonymous satirical review of the première of Jean-Philippe Rameau's Hippolyte et Aricie in October 1733, which was printed in the Mercure de France in May 1734, the critic wrote that the novelty in this opera was "du barocque", complaining that the music lacked coherent melody, was unsparing with dissonances, constantly changed key and meter, and speedily ran through every compositional device.
Jean-Jacques Rousseau, who was a musician and composer as well as philosopher, wrote in 1768 in the Encylopedié: "Baroque music is that in which the harmony is confused, and loaded with modulations and dissonances. The singing is harsh and unnatural, the intonation difficult, and the movement limited. It appears that term comes from the word 'baroco' used by logicians."
The word was first used to describe the period of art that followed the Renaissance in 1855 by the Swiss art historian Jacob Burckhardt in an article in the journal Le Cicerone. He used the term to attack the movement for subverting the values of the Renaissance. The term "style baroque" did not enter into the dictionary of the Académie française until 1878, when it lost its original negative connotation. In 1888, the art historian Heinrich Wölfflin published the first serious academic work on the style, Renaissance und Barock, which described the differences between the painting, sculpture, and architecture of the Renaissance and the Baroque.
The Baroque style of architecture was a result of doctrines adopted by the Catholic Church at the Council of Trent in 1545–63, in response to the Protestant Reformation. The first phase of the Counter-Reformation had imposed a severe, academic style on religious architecture, which had appealed to intellectuals but not the mass of churchgoers. The Council of Trent decided instead to appeal to a more popular audience, and declared that the arts should communicate religious themes with direct and emotional involvement. Lutheran Baroque art developed as a confessional marker of identity, in response to the Great Iconoclasm of Calvinists.