Short answers, pulled from the story.
Baroque is a Western style encompassing architecture, music, dance, painting, sculpture, poetry, and other arts that flourished from the early 1600s until the 1750s. It followed Renaissance art and Mannerism, and used contrast, movement, exuberant detail, deep color, grandeur, and surprise to achieve a sense of awe. The style began in Rome and spread rapidly to the rest of Europe and eventually the Americas and Asia.
The English word baroque comes through French, which may have borrowed it from the Portuguese barroco, meaning a flawed or imperfectly round pearl. A 1694 edition of Le Dictionnaire de l'Academie Francaise defined baroque as applying to pearls that were imperfectly round. The word gained the meaning of bizarre or uselessly complicated partly through the writing of Michel de Montaigne (1533-1592), and was not applied as a positive artistic category until much later.
The Catholic Church encouraged Baroque art as a response to the Protestant Reformation, specifically following doctrines adopted at the Council of Trent (1545-1563). The Church determined that arts should communicate religious themes with direct emotional involvement and appeal to a broad popular audience rather than to intellectuals alone. Baroque churches were designed so worshippers could stand close to the altar, with light streaming from a dome overhead to heighten the sense of the divine.
Gian Lorenzo Bernini and Francesco Borromini were the central figures of Italian Baroque architecture. Bernini designed St. Peter's Baldachin (1623-1634), the Chair of Saint Peter (1647-1653), and the great colonnade of St. Peter's Square (1656-1667). Borromini designed the Church of San Carlo alle Quattro Fontane (1634-1646) and created a famous optical illusion at the Palazzo Spada using diminishing columns to make a seven-meter passage appear thirty meters long.
The invention of the piano is credited to Bartolomeo Cristofori (1655-1731) of Padua, Italy, who was employed by Ferdinando de' Medici, Grand Prince of Tuscany, as the Keeper of the Instruments. Cristofori named it un cimbalo di cipresso di piano e forte, meaning a keyboard of cypress with soft and loud, which was abbreviated over time to pianoforte, fortepiano, and eventually piano.
The first opera theatre in France open to the public was opened in Paris in 1669 by the poet Pierre Perrin. It premiered Pomone, the first grand opera in French, with music by Robert Cambert, featuring five acts, elaborate stage machinery, and a ballet. Opera itself originated in Italy at the end of the sixteenth century, with Jacopo Peri's Dafne, mostly now lost, produced in Florence in 1598.