The third Organ Sonata in Felix Mendelssohn's collection of six, Op. 65, is the briefest and perhaps the brightest of the lot.
It has just two movements, and the A major of the work is an especially shiny kind; it is true, though, that the entire mid-section of the extensive first movement occupies A minor and presents enough wandering chromatic activity enough to avoid tedium.
As he did in the Organ Sonata No. 1, the composer introduces a Lutheran chorale in the first movement. This time the famous "Aus tiefer Not" is the tune chosen, and, in stark contrast to the quiet, unruffled entrance of the chorale tune in Op. 65, No. 1, it enters boldly in the pedals 40 measures into the Con moto maestoso first movement, surrounded by swirling, four-voice counterpoint.
The movement begins in a regal manner, lightly ornamented, sweetly but firmly scored; a move is made, however, to the minor mode, and polyphony starts up to pave the way to the chorale entrance. As the phrases of "Aus tiefer Not" reveal themselves, the pace of the music picks up, and soon sixteenth notes are all the rage (the chorale cantus firmus is, of course, in slow notes throughout), eventually climaxing in a virtuosic passage for the pedals that gradually simmers down into a short reprise of the opening A major homophony.
The second movement occupies just two pages of music; it is an Andante tranquillo whose charming melody came from the same stock as some of the Songs without Words.
(Description by Blair Johnston)