Many of J.S. Bach's most beloved keyboard compositions
were intended partly as instructional material. The six
Trio Sonatas for Organ, BWV 525-530, may be such
pieces; they are thought to have been incorporated into
the lessons that Johann Sebastian gave to his son
Wilhelm Friedemann. The six sonatas were composed close
to the beginning of Bach's life in Leipzig. Unlike some
of the others, which make use of genuine trio sonata
music earlier composed for three players, the first of
them, the Trio...(+)
Many of J.S. Bach's most beloved keyboard compositions
were intended partly as instructional material. The six
Trio Sonatas for Organ, BWV 525-530, may be such
pieces; they are thought to have been incorporated into
the lessons that Johann Sebastian gave to his son
Wilhelm Friedemann. The six sonatas were composed close
to the beginning of Bach's life in Leipzig. Unlike some
of the others, which make use of genuine trio sonata
music earlier composed for three players, the first of
them, the Trio Sonata No. 1 in E flat major for organ,
BWV 525, is apparently a wholly original work.
The process of condensing the by-then venerable trio
sonata medium into music for a single keyboard player
-- with the three original voices assigned to two
manuals and the pedals -- was not accomplished in a
single bold step. Bach's Three-Part Inventions of the
early 1720s draw heavily on trio sonata idioms, as do
several other keyboard works (the B minor Prelude in
the first volume of the Well-Tempered Clavier being a
key example). And we must also remember that while
living in Cöthen in the early 1720s Bach had condensed
the trio sonata texture for two players (e.g. the Six
Sonatas for Violin and Harpsichord, BWV 1014-1019).
Still, BWV 525 is something striking and new: a
full-fledged chamber sonata for a single player, and
probably the first of the organ trio sonatas to be
composed.
Even so, there is very little else that is truly new
about the music of BWV 525 -- the score might easily be
played by two instruments and basso continuo, and very
few listeners would be aware that it is in fact not an
authentic trio sonata. The opening of the first
movement is built by way of the normal upper-voices
imitation, to which the bass voice adds "walking"
eighth notes. The astute listener or player will
certainly notice that the manner of the movement's
active sixteenth notes owes as much to the Baroque
concerto as to the Baroque sonata (as, indeed, does the
late Italian Baroque three-movement format of BWV 525),
but the fusion of sonata and concerto styles is
something that we notice time and again throughout
Bach's chamber sonatas.
The C minor Adagio is in a true binary form whose
rhythms occasionally make quasi-siciliano shapes. The
Allegro finale jumps forth in 3/4 time; the movement
again falls into two halves, and at the start of the
second half Bach turns the main subject of the movement
-- a series of leaping eighth notes and some consequent
sixteenth note runs -- upside down.
Source: Almusic.com
(http://www.allmusic.com/composition/trio-sonata-for-or
gan-no-1-in-e-flat...).
I created this arrangement for String Trio (Violin,
Viola & Cello).