Widespread use of the term concerto appeared in the Baroque period, and by the 1670s, it came to mean an orchestral work with a solo part or multiple parts. The concerto grosso (pl. concerti grossi) is a form of orchestral music primarily associated with this era. It is generally a multi-movement work for a smaller group of solo instruments, called the concertino, contrasted with a larger group, called the ripieno. Alternation between the concertino and the ripieno is a defining characteristic of the mature form of the concerto grosso. However, before the 1670s there had been works with solo instruments contrasting with larger ensembles. Early in the century, particularly in Venice and Bologna, there was a vogue for sinfonias or sonatas for one or more trumpets against string orchestra. In Venice, the birthplace of opera, almost from the beginning it was the practice to precede the opera with an instrumental overture. These were multi-movement works that frequently featured the characteristic contrasts between solo instruments or solo groups and the full ensemble. It was often the case that these instrumental introductions were later played by themselves as independent works.
 
CorelliBefore the end of the 17th century, the concerto grosso ensemble became synonymous with the composition itself, although the term also remained current as a description of the ripieno group. Arcangelo Corelli (left) and Giuseppe Torelli were among the first important authors of concerti grossi. Corelli published one set of 12 Concerti Grossi, Op. 6 (another set, attributed to him, is considered by many to be spurious). They are all for two violins, cello, and a ripieno group of violins, violas, and a bass line played by cellos and string basses. Corelli's concerti grossi are, in form, not much different from his church sonatas, albeit with alternating textures. The smaller group generally creates an echo effect or punctuates the composition. Torelli published his Concerti Grossi, Op. 8, though he left a few more concerti grossi in manuscript. His works show a significant development in form, reflecting the way the concerto principle was used in opera. His first movements began with a ritornello (refrain) section developing one or two main thematic ideas. This is followed by a solo passage based on different material. The fuller orchestra then returned with a variant of the ritornello, in a different key. This sort of alternation continued throughout the movement, with a final statement of the ritornello in the home key, practically identical to the opening ritornello. The second movement was a tripartite scheme comprising two Adagio sections separated by a brief Allegro portion. The final movements are lighter fast movements along similar lines as the opening movement.
 
VivaldiThe next significant Italian composers writing concerti grossi were Francesco Geminiani and Antonio Vivaldi (right). Geminiani used the four-movement sonata di chiesa or church sonata form (slow-fast-slow-fast) in his concertos, while Corelli had used usually about five. Geminiani's concerti are conservative in approach, and the concerto grosso is treated as a sonata with alternating textures, like Corelli's. Vivaldi's more concise concertos standardized the number of movements to three: fast-slow-fast. In all his concertos he replaced contrapuntal textures with the texture generally made of a melody line over figurations in the other parts. He wrote hundreds of solo concertos and concertos for two instruments, and about three dozen concertos for multiple instruments, most of which would count as concerti grossi. These are works that make a brilliant effect. They possess great variety in their instrumentation: some are for string groups, some have wind concertinos, and others mix winds and strings.
 
Other important composers of concert grossi at the time were Tomaso Albinoni and the German-Italian Evaristo Felice dall'Abaco.
 
HandelMeanwhile, the broad idea of the concerto, including the concerto grosso, spread to Germany at the start of the 18th century. Georg Muffat is credited with introducing the concept to Germany. Muffat, saying that he encountered the form while visiting in Italy, fashioned his works so they could be played in various ways, as solo sonatas or in larger groupings, depending on the availability of musicians. The greatest concerti grossi were, not surprisingly, written by George Frederick Handel (left) and Johann Sebastian Bach. Both composers modeled their works after Vivaldi's style, although without strictly adhering to Vivaldi's three-movement form. Handel published two sets of concerti grossi and a separate concerto grosso called Alexander's Feast. One of the sets, Opus 6, is a set of 12 concertos for two violins, cello, and strings. The six concertos of Opus 3 are for more diverse groupings, such as two oboes, two violins, two cellos, and strings; or two oboes, bassoon, and strings.
 
BachThe most famous concerti grossi are the six that Bach (right) composed, ostensibly as audition pieces for a position with the Margrave of Brandenburg, collectively known as the Brandenburg Concertos. Each of the six is for a different line-up of instruments:
 
Concerto No. 1 in F major: Two corni di caccia (natural horns), 3 oboes, bassoon, and piccolo violin in the concertino, with a ripieno of strings and basso continuo;
Concerto No. 2 in F major: Trumpet, recorder, oboe, violin, and a string ripieno with basso continuo;
Concerto No. 3 in G major: Three violins, three violas, three cellos, and basso continuo;
Concerto No. 4 in G major: Violin, two recorders, and a string ripieno with basso continuo;
Concerto No. 5 in D major: Flute, violin, and harpsichord, with a string ripieno and basso continuo;
Concerto No. 6 in B flat major: Two violas, two viole da gamba, cello, violone, and harpsichord.
Others of Bach's works might be classed as concerti grossi, including the Double Violin Concerto and the concertos for multiple harpsichords.
 
Of composers younger than Bach and Handel, Pietro Locatelli and Francisco Manfredini wrote significant concerti grossi, but the form essentially died out with their deaths. During the Classical and Romantic eras the form was virtually unknown; the small number of double and triple concertos of the time ordinarily were conceived with the solo instruments cast as individuals. Thus, they lack the important distinguishing characteristic of the concerto grosso, which is the assembling of the concertino group into a distinct contrasting unit. During this period, the important compositions nearest to the concerto grosso model are the Classical sinfonias concertantes by Wolfgang Amadeus Mozart and Franz Joseph Haydn.
 
StravinskyThe neo-Classical movement of the early 20th century reintroduced the concerto grosso as part of a "Back to Bach" campaign. A key example is the "Dumbarton Oaks" Concerto of Igor Stravinsky (left), which was pointedly modeled on the Brandenburg Concertos. So were the ten Strathclyde Concertos by Peter Maxwell Davies, some of which are for multiple instruments. This form of 20th century concerto grosso is viewed as a reaction against the flamboyant display of the typical Romantic era solo concerto and often makes much the same effect as it did in the Baroque: a balanced conversation between the two major textures rather than a contest between them. Bohuslav Martinu in particular was fond of writing of multiple-instrument concertos. His catalog includes a Concerto for string quartet & orchestra, a Concerto da Camera for violin, piano, percussion, and strings, and a Concerto Grosso for two pianos and chamber orchestra.
 
William Alwyn, Ernest Bloch, Morton Gould, Alfred Schnittke, Ralph Vaughan Williams, and Ellen Taafe Zwillich are among several 20th century composers to write significant concerti grossi, and many others have written works exhibiting the concertino/ripieno principle. Béla Bartók's Divertimento for strings, for instance, frequently switches from full string orchestra to string quartet, although the alternations are rapid-fire, not falling into the ritornello-concertino sections of a Baroque concerto grosso. In his Triple Concerto a Tre, Gian Carlo Menotti composed a remarkable and attractive work which is in reality a concerto grosso, though with a different three-part concertino group in each of its three movements.