The six organ sonatas by Felix Mendelssohn (1809 - 1847) are not sonatas in the classical sense of that term. Rather, they are a collection of multi-movement suites, composed mostly between 1844 and 1845 - just after his founding the Leipzig Conservatory. By the time these sonatas were composed, Mendelssohn was well known as composer, pianist, and organist, having made many tours as a soloist throughout Germany and England. His improvisations were highly regarded; and it was while on tour in England that he was approached, by a publisher there, to compose some works for the organ. The 35-year-old Mendelssohn may have wanted to impress his English colleagues, or perhaps even show them up, because he composed works with extremely virtuosic pedal parts, at a time in history when English organists had limited pedal technique. Perhaps he wanted to assert his lineage to the great Bach tradition and the magnificent German organs which influenced his tonal palette. Regardless, his masterworks for organ are justly regarded as the finest examples of Classical German organ literature.

Although Mendelssohn made numerous corrections and changes to the first two published editions (Coventry, London and Breitkopf & Härtel, Leipzig), there are no indications of registration choices. In his "Prefatory Remarks" he says:
"Much depends in these Sonatas on the right choice of the Stops; however, as every Organ with which I am acquainted has its own peculiar mode of treatment in this respect, and as the same nominal combination does not produce exactly the same effect in different iInstruments, I have given only a general indication of the kind of effect intended to be produced, without giving a precise List of the particular Stops to be used. By "Fortissimo" I intend to designate the Full Organ; by "Pianissimo" I generally mean a soft 8 foot Stop alone; by "Forte" the Great Organ, but without some of the most powerful Stops; by "Piano" some of the soft 8 foot Stops combined; and so forth. In the Pedal part, I should prefer throughout, even in the Pianissimo passages, the 8 foot and the 16 foot Stops united; except when the contrary is expressly specified; (see the Sixth Sonata). It is therefore left to the judgment of the Performer, to mix the different Stops appropriately to the style of the various Pieces; advising him, however, to be careful that in combining the Stops belonging to two different sets of keys, the kind of tone in the one, should be distinguished from that in the other; but without forming too violent a contrast between the two distinct qualities of tone."

These pieces are marked by two "Affekts," strength and beauty. From the full and dramatic F minor chords of the opening sonata to the toccata-style final variation of "Vater unser im Himmelreich" (Sonata 6), it is clear that this is intensely masculine, strong, technically demanding, and emotionally assertive music. Yet the magic of Mendelssohn's pieces lies in his ability to play with light and shadow so convincingly. Assertiveness yields to lyricism and gentleness over and over again. In the midst of an angry opening section of Sonata 1, a simply-stated, soft chorale ("Was mein Gott will, das g'scheh' allzeit") enters to calm the storm. Slow movements of heart-rending beauty blend the yin and yang of his musical vocabulary as if he were touching our very soul.

It is this assimilation of the Romantic sentiment expressed within Classical and Baroque forms that makes this music so important to us today. The lineage from Bach to Mendelssohn is clear. But looking forward, we can also see how Mendelssohn's Romantic side influenced the music of Schumann, Brahms, and Liszt. The organ, as an instrument, was undergoing tonal changes in the early nineteenth century; and it's likely that Mendelssohn, as an international concert performer, and the students and colleagues he directly influenced (Richter, Gade, Becker, van Eyken) was the most significant force in establishing this change.

- Jonathan Dimmock
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