Baroque music (UK: // or US: //) is a period or style of Western art music composed from approximately 1600 to 1750. This era followed the Renaissance music era, and was followed in turn by the Classical era, with the galant style marking the transition between Baroque and Classical eras. The Baroque period is divided into three major phases: early, middle, and late. Overlapping in time, they are conventionally dated from 1580 to 1650, from 1630 to 1700, and from 1680 to 1750. Baroque music forms a major portion of the "classical music" canon, and is now widely studied, performed, and listened to. The term "baroque" comes from the Portuguese word barroco, meaning "misshapen pearl". Key composers of the Baroque era include Johann Sebastian Bach, Antonio Vivaldi, George Frideric Handel, Claudio Monteverdi, Domenico Scarlatti, Alessandro Scarlatti, Henry Purcell, Georg Philipp Telemann, Jean-Baptiste Lully, Jean-Philippe Rameau, Marc-Antoine Charpentier, Arcangelo Corelli, François Couperin, Giuseppe Tartini, Heinrich Schütz, Dieterich Buxtehude, and others.
The Baroque period saw the creation of common-practice tonality, an approach to writing music in which a song or piece is written in a particular key; this type of harmony has continued to be used extensively in Western classical and popular music. During the Baroque era, professional musicians were expected to be accomplished improvisers of both solo melodic lines and accompaniment parts. Baroque concerts were typically accompanied by a basso continuo group (comprising chord-playing instrumentalists such as harpsichordists and lute players improvising chords from a figured bass part) while a group of bass instruments—viol, cello, double bass—played the bassline. A characteristic Baroque form was the dance suite. While the pieces in a dance suite were inspired by actual dance music, dance suites were designed purely for listening, not for accompanying dancers.
During the period, composers experimented with finding a fuller sound for each instrumental part (thus creating the orchestra), made changes in musical notation (the development of figured bass as a quick way to notate the chord progression of a song or piece), and developed new instrumental playing techniques. Baroque music expanded the size, range, and complexity of instrumental performance, and also established the mixed vocal/instrumental forms of opera, cantata and oratorio and the instrumental forms of the solo concerto and sonata as musical genres. Dense, complex polyphonic music, in which multiple independent melody lines were performed simultaneously (a popular example of this is the fugue), was an important part of many Baroque choral and instrumental works. Overall, Baroque music was a tool for expression and communication.