Maurice Ravel (1875-1937) was never a prolific composer, and his output for chamber media was correspondingly sparse. After completing his String Quartet in 1903 as a student at the Paris Conservatoire, Ravel wrote little chamber music of significance until embarking on his Piano Trio in 1914. Early that year the composer retired to the countryside to work uninterrupted, but he soon developed problems. One was his preoccupation with a proposed piano concerto on Basque themes, which never materialized. Then, during the early summer, he seems to have experienced a form of writer's block, and he became disgusted with his work on the Trio. Finally, when France entered World War I in August, Ravel became determined to finish the work quickly, so that he could volunteer for military service. He worked feverishly at the Trio during August and wrote to a friend,

"I am working --- yes, working with the sureness and lucidity of a madman. At the same time I get terrible fits of depression and suddenly find myself sobbing over the sharps and flats!" By the end of the month, Ravel had finished what many consider one of the most significant chamber works of the 20th century.

In the first movement, cast roughly in sonata form, the most striking feature is the rhythm. The metre marking is 8/8, and the resulting asymmetrical rhythmic design of each measure is usually some variant of 3 + 2 + 3 quavers. This is the Bulgarian rhythm, which Bartok used frequently, but it is also the rhythm of certain Basque dances which Ravel was thinking about at the time he wrote the Trio.

Rhythm and metre are also critical factors in the second movement, "Pantoum." A "pantoum" (or "phantoum") is a poetic form of probable Malayan origin, used by Baudelaire and other French poets. It consists of bringing back two lines of one quatrain in the following one, which gives the impression of two distinct ideas juxtaposed. Ravel carries out this principle in both the structure and the rhythm of this high-spirited movement. The alternations and combinations of mosaic themes of the movement are crowned in the middle by an extended passage in polymeter. Here, the strings continue in the original metre of 3/4, while the piano accompanies with rich chords in 2/2 time.

The third movement is a formally strict 20th-century adaptation of the Baroque French Passacaille, a contrapuntal variation form. The nature of this movement hints at why Ravel dedicated his Trio to Andre Gedalge, the famous contrapuntist and Ravel's former teacher.

In the Trio's brilliant finale, written in a free rondo form, asymmetrical rhythm again comes into play. Passages in 5/4 time alternate with 7/4 segments. Ravel also becomes more orchestral and virtuosic in this movement, with its shimmering cello tremolos and quick violin arpeggios. Rich, thick chords in the piano work rhythmically both with and against the strings to give the impression of "floating" metre, a feature that strongly unifies the entire Trio.