What Is a Concerto? One Player Against the Whole Orchestra

The term comes into use in Italy around 1600 and its origin is contested in a way that suits the form. One derivation is from the Latin concertare, to contend or dispute; another is from conserere, to join together, and Italian usage carries both senses, so that the word means either a struggle or a partnership depending on which etymology you prefer. Early uses did not mean what it means now, since a concerto in the early seventeenth century could be any piece for mixed voices and instruments. The modern sense, a work in several movements for a soloist and orchestra, settles during the decades around 1700, and it emerged from a related form, the concerto grosso, in which a small group of players rather than a single soloist is set against the larger body, the arrangement used in Corelli's sets and in Bach's Brandenburg collection.

More than five hundred of them survive by Antonio Vivaldi alone, written largely for the orchestra of a Venetian institution for orphaned girls, and it was he who standardised the design that the next century inherited. The scheme has three movements, fast, slow, fast, and the fast movements use a structure called ritornello form:

• •The full orchestra states a theme, the ritornello, which is memorable and usually built of short repeatable units
• •The soloist takes over with new or developed material, often more elaborate and harder to play
• •The orchestra returns with the theme, or part of it, in a different key
• •The alternation continues, with the soloist modulating between statements, until the theme comes back in the home key to close
• •The slow middle movement drops most of the orchestra and gives the soloist a long singing line, which is where the emotional weight usually sits

The classical period absorbed the form into sonata principles, and Mozart's twenty-seven piano concertos are generally treated as the point at which the genre becomes fully expressive rather than decorative, with the orchestra promoted from accompanist to genuine partner and the wind writing carrying material of its own. The first movement acquired a double exposition, in which the orchestra presents the themes and the soloist then enters and presents them again, which is a formal solution to a practical problem about when the star should arrive. Near the end of the movement the orchestra stops on a chord and the soloist plays alone, unaccompanied and originally improvised, in the passage called the cadenza, which is where a performer demonstrated invention as well as technique. Beethoven ended that tradition by writing his own cadenzas out, most emphatically in his fifth piano concerto where the score instructs the player not to improvise, and from then on the improvised cadenza largely disappeared, though a handful of modern performers have revived it.

The nineteenth century turned the soloist into a public figure and the form into a display of what a human being could do with an instrument. Paganini's violin playing was so far beyond his contemporaries that a rumour circulated about a bargain with the devil, and Liszt did the equivalent at the piano, inventing the solo recital in the process. The concerto followed: works became longer and technically brutal, the orchestra grew, and the emotional register widened, producing the Brahms, Tchaikovsky, Mendelssohn, Dvorak and Grieg works that still dominate concert programming. Several were declared unplayable when new, including the Tchaikovsky violin concerto, which one critic described as music that stinks to the ear, and which is now standard repertoire for conservatoire students. The touring virtuoso with a signature concerto is a business model invented in this period and still operating.

The twentieth century kept the form and questioned its premise. Bartok, Prokofiev, Shostakovich, Berg and Ligeti all wrote concertos that treat the soloist as something other than a hero, and Bartok wrote a Concerto for Orchestra whose title is a deliberate paradox, treating the sections of the orchestra as soloists in turn. Jazz absorbed the idea directly, since the alternation of a stated theme and an improvised solo over a rhythm section is structurally the ritornello principle, and Gershwin's Rhapsody in Blue sits deliberately between the two worlds. Concertos exist now for almost anything, including percussion, harmonica, turntables and, in one case by Ligeti, a solo horn quartet. What has not changed is the basic theatrical situation, which is one person, exposed, playing from memory, in front of an ensemble that can bury them, and the audience knowing it.

The form sets one player against an orchestra, and its name carries both the sense of contending and of joining together. Vivaldi fixed the three-movement fast, slow, fast design and the ritornello structure in which orchestral statements of a theme alternate with solo episodes. Mozart made the orchestra a genuine partner and added the double exposition, Beethoven ended the improvised cadenza by writing his own out, the nineteenth century turned the soloist into a celebrity, and the twentieth kept the form while questioning the heroism behind it.