Because the arts present such diversity within the Baroque period, their unifying characteristics must be sought in relation to the era's broader cultural and intellectual tendencies, of which three are most important for their effect on the arts. The first of these was the emergence of the Counter-Reformation and the expansion of its domain, both territorially and intellectually. By the last decades of the 16th century the refined, courtly style known as Mannerism had ceased to be an effective means of expression, and its inadequacy for religious art was being increasingly felt in artistic circles. To counter the inroads made by the Reformation, the Roman Catholic Church after the Council of Trent (1545–63) adopted a propagandistic stance in which art was to serve as a means of extending and stimulating the public's faith in the church. To this end the church adopted a conscious artistic program whose art products would make an overtly emotional and sensory appeal to the faithful. The Baroque style that evolved from this program was paradoxically both sensuous and spiritual; while a naturalistic treatment rendered the religious image more accessible to the average churchgoer, dramatic and illusory effects were used to stimulate piety and devotion and convey an impression of the splendour of the divine. Baroque church ceilings thus dissolved in painted scenes that presented vivid views of the infinite to the observer and directed the senses toward heavenly concerns.

The second tendency was the consolidation of absolute monarchies, accompanied by a simultaneous crystallization of a prominent and powerful middle class, which now came to play a role in art patronage. Baroque palaces were built on an expanded and monumental scale in order to display the power and grandeur of the centralized state, a phenomenon best displayed in the royal palace and gardens at Versailles (Versailles, Palace of). Yet at the same time the development of a picture market for the middle class and its taste for realism may be seen in the works of the brothers Le Nain and Georges de La Tour in France and in the varied schools of 17th-century Dutch painting.

The arts present an unusual diversity in the Baroque period, chiefly because currents of naturalism and classicism (Classicism and Neoclassicism) coexisted and intermingled with the typical Baroque style. Indeed, Annibale Carracci (Carracci, Annibale) and Caravaggio, the two Italian painters who decisively broke with Mannerism in the 1590s and thus helped usher in the Baroque style, painted, respectively, in classicistic and realist modes. A specifically Baroque style of painting arose in Rome in the 1620s and culminated in the monumental painted ceilings and other church decorations of Pietro da Cortona, Guido Reni, Il Guercino, Domenichino, and countless lesser artists. The greatest of the Baroque sculptor-architects was Gian Lorenzo Bernini (Bernini, Gian Lorenzo), who designed both the baldachin with spiral columns above the altar of St. Peter's in Rome and the vast colonnade fronting that church. Baroque architecture (Western architecture) as developed by Bernini, Carlo Maderno, Francesco Borromini, and Guarino Guarini emphasized massiveness and monumentality, movement, dramatic spatial and lighting sequences, and a rich interior decoration using contrasting surface textures, vivid colours, and luxurious materials to heighten the structure's physical immediacy and evoke sensual delight.

The Baroque made only limited inroads into northern Europe, notably in what is now Belgium. That Spanish-ruled, largely Roman Catholic region's greatest master was the painter Peter Paul Rubens (Rubens, Peter Paul), whose tempestuous diagonal compositions and ample, full-blooded figures are the epitome of Baroque painting. The elegant portraits of Anthony Van Dyck and the robust figurative works of Jacob Jordaens emulated Rubens's example. Art in Holland was conditioned by the realist tastes of its dominant middle-class patrons, and thus both the innumerable genre and landscape painters of that country and such towering masters as Rembrandt and Frans Hals remained independent of the Baroque style in important respects. The Baroque did have a notable impact in England, however, particularly in the churches and palaces designed, respectively, by Sir Christopher Wren and Sir John Vanbrugh.

The last flowering of the Baroque was in largely Roman Catholic southern Germany and Austria, where the native architects broke away from Italian building models in the 1720s. In ornate churches, monasteries, and palaces designed by J.B. Fischer von Erlach, J.L. von Hildebrandt, the Asam brothers, Balthasar Neumann, and Dominikus Zimmermann, an extraordinarily rich but delicate style of stucco decoration was used in combination with painted surfaces to evoke subtle illusionistic effects.

One of the most dramatic turning points in the history of music (music, Western) occurred at the beginning of the 17th century, with Italy again leading the way. While the stile antico, the universal polyphonic style of the 16th century, continued, it was henceforth reserved for sacred music, while the stile moderno, or nuove musiche—with its emphasis on solo voice, polarity of the melody and the bass line, and interest in expressive harmony—developed for secular usage. The expanded vocabulary allowed for a clearer distinction between sacred and secular music as well as between vocal and instrumental idioms, and national differences became more pronounced. The Baroque period in music, as in other arts, therefore, was one of stylistic diversity. The opera, oratorio, and cantata were the most important new vocal forms, while the sonata, concerto, and overture were created for instrumental music. Claudio Monteverdi (Monteverdi, Claudio) was the first great composer of the “new music.” He was followed in Italy by Alessandro Scarlatti and Giovanni Pergolesi. The instrumental tradition in Italy found its great Baroque composers in Arcangelo Corelli, Antonio Vivaldi, and Giuseppe Tartini. Jean-Baptiste Lully, a major composer of opera, and Jean Philippe Rameau were the masters of Baroque music in France. In England the total theatrical experience of the Stuart masques was followed by the achievements in vocal music of the German-born, Italian-trained George Frideric Handel, while his countryman Johann Sebastian Bach developed Baroque sacred music in Germany. Other notable German Baroque composers include Heinrich Schütz, Dietrich Buxtehude, and Georg Philipp Telemann.