Ludwig van Beethoven's Concerto for Violin, Cello, and Piano in C major, Op. 56, more commonly known as the Triple Concerto, was composed in 1803 and later published in 1804 under Breitkopf & Härtel. The choice of the three solo instruments effectively makes this a concerto for piano trio, and it is the only concerto Beethoven ever completed for more than one solo instrument. A typical performance takes approximately thirty-seven minutes.
Beethoven's early biographer Anton Schindler claimed that the Triple Concerto was written for Beethoven's royal pupil, the Archduke Rudolf of Austria. The Archduke, who became an accomplished pianist and composer under Beethoven's tutelage, was only in his mid-teens at this time, and it seems plausible that Beethoven's strategy was to create a showy but relatively easy piano part that would be backed up by two more mature and skilled soloists. However, there is no record of Rudolf ever performing the work—it was not publicly premiered until 1808, at the summer "Augarten" concerts in Vienna—and when it came to be published, the concerto bore a dedication to a different patron: Prince Lobkowitz (Franz Joseph Maximilian Först von Lobkowitz).
The first movement is broadly scaled and cast in a moderate march tempo, and includes decorative solo passage-work and leisurely repetitions, variations, and extensions of assorted themes. A common feature is a dotted rhythm (short-long, short-long) that lends an air of graciousness and pomp that is not exactly "heroic," but would have conveyed a character of fashionable dignity to contemporary listeners; and perhaps a hint of the noble "chivalric" manner that was becoming a popular element of novels, plays, operas, and pictures. The jogging triplets that figure in much of the accompaniment also contribute to this effect. In this movement, as in the other two movements, the cello enters solo with the first subject. Unusual for a concerto of this scale, the first movement begins quietly, with a gradual crescendo into the exposition, with the main theme later introduced by the soloists. Also unusually, the exposition modulates to A minor instead of the expected G major (Beethoven's friend Ferdinand Ries later did the same mediant transition in his sixth concerto). This movement takes sixteen to nineteen minutes.
The slow movement, in A-flat major, is a large-scale introduction to the finale, which follows it without pause. The cello and violin share the melodic material of the movement between them while the piano provides a discreet accompaniment. This movement takes about only five to six minutes.
Dramatic repeated notes launch into the third movement, a polonaise (also called "polacca"), an emblem of aristocratic fashion during the Napoleonic era, which is, thus, in keeping with the character of "polite entertainment" that characterizes this concerto as a whole. The bolero-like rhythm also characteristic of the polonaise, can be heard in the central minor theme of the final movement. This movement takes about thirteen to fourteen minutes.
In addition to the violin, cello, and piano soloists, the concerto is scored for one flute, two oboes, two clarinets, two bassoons, two horns, two trumpets, timpani, and strings. The flute, oboes, trumpets, and timpani are tacet during the second movement.
Source: Wikipedia