Felix Mendelssohn's Piano Trio No. 1 in D minor, Op. 49 was completed on 23 September 1839 and published the following year. The work is scored for a standard piano trio consisting of violin, cello and piano. The trio is one of Mendelssohn's most popular chamber works and is recognized as one of his greatest along with his Octet, Op. 20.

During the initial composition of the work, Mendelssohn took the advice of a fellow composer, Ferdinand Hiller, and revised the piano part. The revised version was in a more romantic, Schumannesque style with the piano given a more important role in the trio. Indeed, the revised piece was reviewed by Schumann who declared Mendelssohn to be "the Mozart of the nineteenth century, the most illuminating of musicians."

Movements

The trio has four movements:

1. Molto allegro ed agitato (D minor)
2. Andante con moto tranquillo (B-flat major)
3. Scherzo: Leggiero e vivace (D major)
4. Finale: Allegro assai appassionato (D minor, ending in D major)

A typical performance lasts just under 30 minutes.

Molto allegro ed agitato

The first movement is in sonata form and begins without an introduction with a cantabile main theme played by the cello, with the piano providing a syncopated accompaniment. The violin then joins the cello with a distorted version of the theme. Further variations of the main theme fill the transition to the second theme, also introduced by the cello, which is in A major. Mendelssohn combines both themes in the development, which is predominately in D minor, the key in which the movement also ends. In the recapitulation, Mendelssohn adds a violin counter-melody to support the return of the original theme.

Andante con moto tranquillo

The piano introduces the second movement, with the eight bar melody in the right hand and the accompaniment divided between the hands, as in a number of Mendelssohn's Songs without Words. Below this, the bass line in the piano moves methodically, carefully balancing with the accompaniment and the melody. After the piano plays the main theme, the violin repeats it with a counterpoint played on the cello.

Scherzo

The short and light scherzo is essentially in sonata form. As in the second movement, the main theme is first played on the piano, which then reduces itself to fragmentary accompaniment almost immediately. A rhythmical motif of the main theme is present throughout the movement, except in the more lyrical central section, whose theme resembles material from the first movement.

Finale

After Hiller gave Mendelssohn his advice, the finale was the most revised movement and unsurprisingly has a busy piano part. Various keyboard techniques are called upon in the movement, from close chords to sweeping arpeggios and chromatic octaves. The cantabile moments provide a refreshing contrast. The trio finishes with the shift to D major shortly before the end.