In music, a suite is an organized set of instrumental or orchestral pieces normally performed at a single sitting. In the Baroque era, the pieces are all in the same key, and generally modelled after dance music. In the eighteenth century suites were also known as overtures or ouvertures.
Estienne du Tertre published suyttes de bransles in 1557, giving us the first use of the term, although the usual form of the time was as pairs of dances. The first recognizable suite is Peuerl's Newe Padouan, Intrada, Dantz, and Galliarda of 1611, in which the four dances of the title appear repeatedly in ten suites. The Banchetto musicale by Schein (1617) contains 20 sequences of five different dances.
The "classical" suite consisted of allemande, courante, sarabande, and gigue, in that order, and developed during the 17th century in France, the gigue appearing later than the others. However, it was never totally fixed in form, and the later addition of an overture to make up an "overture-suite" was extremely popular with German composers; Telemann claimed to have written over 200, Bach had his four orchestral suites, and Handel put his Water Music and Music for the Royal Fireworks in this form.
Bach and Handel frequently added additional pieces between the sarabande and gigue; Handel wrote 22 keyboard suites, while Bach produced multiple suites for cello, violin, flute, and other instruments, as well as his French suites and English suites for keyboard. For Bach especially, the suite form was a base on which to spin more elaborate sequences.
By the 1750s however, the suite had come to be seen as old-fashioned, superseded by symphony and concerto, and we see few composers still writing suites. In the 19th century the term made a comeback, but now meaning either an instrumental selection from a larger work such as an opera or ballet, a sequence of smaller pieces tied together by a common theme, such as the nationalistic ideas of Grieg, Sibelius, or Tchaikovsky, or as a deliberately archaism, as in the recent Suite for Flute and Jazz Piano by Claude Bolling.
Suite is also used of other kinds of organized collections, ranging from furniture to software (as in office applications suite).