The Piano Trio No 2 in C minor Op 66 followed six years after the D minor, in 1845, and was dedicated to violinist Louis Spohr. Mendelssohn wrote to him, ‘I would like to have saved the honour for a somewhat longer piece, but then I should have had to put it off, as I have so often of late. Nothing seemed good enough to me, and in fact neither does this trio.’ Mendelssohn’s energy and health were beginning to fail, and he had retired from his orchestral duties. But there is no sign of weakness in the C minor Trio. It is as fine a work as its companion, and if it has never been as popular as the D minor, this is because it does not wear its melody on its sleeve in quite the same way.

For Mendelssohn’s generation, writing a work in C minor had a particular resonance from the music of Mozart and Beethoven. Mozart’s Piano Concerto in C minor was greatly admired by Beethoven for its uniquely ambivalent mood of serene tragedy. Beethoven’s works in C minor have a characteristically rugged seriousness of purpose, the ‘Pathétique’ Sonata, Fifth Symphony, and Overture to Coriolan, and they in turn were admired by Mendelssohn and his contemporaries. With the 16th century chorale on which the last movement is based, known in the English-speaking world as ‘The Old Hundredth’, Mendelssohn offers to the listener his own contemplation of ancient religious music, and a majestic climax, which shows that Mendelssohn shared the Romantic vision of the sacred as personal experience, as an aspect of the sublime.

Following a flurry of activity as a composer of string quartets in 1813, at the tender age of sixteen, Schubert wrote only three further quartets during his period of apprenticeship—one in each of the three succeeding years. Looking back on his early efforts in the summer of 1824, just a few months after he had completed his ‘Death and the Maiden‘ Quartet, he seems to have had scant regard for them. Over the string quartet, as over the piano sonata, loomed the giant figure of Beethoven, and perhaps it was unwise of Schubert to have chosen to make his return to the quartet arena with a piece in C minor—the key Beethoven had made so much his own.

On 2 October 1828 Schubert wrote to the Leipzig music publisher Heinrich Albert Probst, informing him: ‘Among other things, I have composed three sonatas for piano solo, which I should like to dedicate to Hummel. I have also set several poems by Heine of Hamburg, which went down extraordinarily well here, and finally have completed a Quintet for 2 violins, 1 viola and 2 violoncellos. I have played the sonatas in several places, to much applause, but the Quintet will only be tried out in the coming days. If any of these compositions are perhaps suitable for you, let me know.’ Six weeks later, Schubert was dead at the age of thirty-one, without having seen any of this miraculous outpouring of music in print.

In adding a second cello to the normal string quartet, rather than a second viola (as in the great quintets by Mozart), Schubert was following the example of the many similarly scored works by Boccherini. Boccherini was one of the greatest cellists of his day, and as court composer to King Friedrich II of Prussia his easiest means of pleasing his cello-playing employer was to give him the comparatively undemanding bass-line of the ensemble, and to allow the first cello a florid, high-lying part. What Schubert wanted to do, on the other hand, was to exploit the warm sound of the combined cellos—as he does so strikingly in the memorable second theme of the opening movement, and in one of the episodes of the finale. At other times, Schubert uses violin and cello in octaves, to intensify the melodic line, as in the passionate middle section of the slow movement, and the sombre trio of the scherzo.